Compare Claude Sonnet 4.5 and Claude Sonnet 4.6: Same Pricing, Better Agents
Claude Sonnet 4.5 vs Claude Sonnet 4.6: which should I use?
Claude Sonnet 4.6 replaces Sonnet 4.5 at the exact same token price ($3.00/$15.00 per million tokens) with improved autonomous tool call reliability and fewer hallucinated imports. Verified 2026-09-07.
Verified 2026-09-07
Where can you find price, speed, and task evidence for Claude Sonnet 4.5 and Claude Sonnet 4.6?
Which tasks fit Claude Sonnet 4.5 and Claude Sonnet 4.6?
Best-fit task signals from the published model strengths; this is not a substitute for a controlled benchmark.
| Fact | Claude Sonnet 4.5 | Claude Sonnet 4.6 |
|---|---|---|
| Best fit | Intermediate Claude 4.5 workflows superseded by Sonnet 4.6. | Enterprise workloads that need Opus-adjacent quality at Sonnet pricing. |
| Reasoning mode | Available | Available |
What does a Coding Agent workload cost with Claude Sonnet 4.5 and Claude Sonnet 4.6?
Modeled for Coding Agent: 20,000 input + 2,000 output tokens per task, 1 turn. This is a workload model, not a provider quote.
| Fact | Claude Sonnet 4.5 | Claude Sonnet 4.6 |
|---|---|---|
| Coding Agent / task | $0.09 (modeled) | $0.09 (modeled) |
| Input / output rate | $3.00 / $15.00 per M | $3.00 / $15.00 per M |
How fast are Claude Sonnet 4.5 and Claude Sonnet 4.6?
Only non-estimated benchmark results are shown as measured.
| Fact | Claude Sonnet 4.5 | Claude Sonnet 4.6 |
|---|---|---|
| Measured throughput | Unavailable | 76 tokens/s |
| Time to first token | Unavailable | 360 ms |
How compatible are Claude Sonnet 4.5 and Claude Sonnet 4.6 with APIs?
Provider-level wire-format and SDK facts; model-specific parameter differences may still apply.
| Fact | Claude Sonnet 4.5 | Claude Sonnet 4.6 |
|---|---|---|
| OpenAI SDK | Not drop-in | Not drop-in |
| Request shape | Messages API — system prompt is a top-level field, not a message role, and max_tokens is required on every call. | Messages API — system prompt is a top-level field, not a message role, and max_tokens is required on every call. |
| Streaming | SSE (Anthropic content-block events) | SSE (Anthropic content-block events) |
What are the privacy and retention policies for Claude Sonnet 4.5 and Claude Sonnet 4.6?
Provider policy and residency facts from the verified provider registry. A missing retention policy is not treated as a guarantee.
| Fact | Claude Sonnet 4.5 | Claude Sonnet 4.6 |
|---|---|---|
| Provider says API data trains models | No | No |
| Published retention period | Unavailable | Unavailable |
| Data residency | Unavailable | Unavailable |
How much effort does it take to migrate between Claude Sonnet 4.5 and Claude Sonnet 4.6?
Direction is from each displayed model to the other. Effort is derived from provider compatibility and published parameter maps.
| Fact | Claude Sonnet 4.5 | Claude Sonnet 4.6 |
|---|---|---|
| Move Claude Sonnet 4.5 → Claude Sonnet 4.6 | drop-in; 0 breaking parameter differences | Target: Claude Sonnet 4.6 |
| Move Claude Sonnet 4.6 → Claude Sonnet 4.5 | Source: Claude Sonnet 4.6 | drop-in; 0 breaking parameter differences |
| Why | Same provider; only the model identifier changes. | Same provider; only the model identifier changes. |
Batch 54 · exact pair cutover and operating-tier contributions. Surface verification: 2026-09-02. These exactly three boards are server-rendered from frozen scenario fixtures; assumptions and unavailable joins are not observations.
Exact pair boundary: Anthropic; same-family adjacent versions; pin exact version rather than floating alias. Requested models are claude-sonnet-4-5 and claude-sonnet-4-6. Provider, rate, pricing, and task pages remain fact owners.
Sonnet 4.5-to-4.6 contract delta compiler
Frozen Batch 54 scenario board. Formula / deterministic rule: migration_safe = exact version + semantic mapping + cache/token consequence + probe pass; floating alias => block Boundary: Owns only adjacent Sonnet 4.5-to-4.6 contract drift, not Sonnet 4 estate migration or Sonnet 5 choice.
| Frozen scenario / field ID | Pair, host, surface, and evidence fields | Result | State |
|---|---|---|---|
batch54-claude-sonnet-4-5-vs-claude-sonnet-4-6-m1-r1ordinary text | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-sonnet-4-5,claude-sonnet-4-6; effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; version=4.5→4.6 pinned; prompt/config hash=sonnet-contract-001; response fields=required; cache consequence=probe; evidence=2026-09-02 | Admit only after response shape and cache behavior are asserted on exact versions. | CONDITIONAL — contract probe |
batch54-claude-sonnet-4-5-vs-claude-sonnet-4-6-m1-r2extended thinking | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-sonnet-4-5,claude-sonnet-4-6; effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; thinking=extended; versions=pinned; config hash=sonnet-contract-002; reasoning token accounting=required; result hash=missing; evidence=2026-09-02 | Unavailable — thinking-token and result joins are absent | UNAVAILABLE — reasoning delta |
batch54-claude-sonnet-4-5-vs-claude-sonnet-4-6-m1-r3adaptive thinking | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-sonnet-4-5,claude-sonnet-4-6; effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; thinking=adaptive; alias=forbidden; control/value=required; effective version=required; client fallback=required; evidence=2026-09-02 | Unavailable — adaptive-control semantics are not joined for both versions | UNAVAILABLE — control mapping |
batch54-claude-sonnet-4-5-vs-claude-sonnet-4-6-m1-r4strict schema | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-sonnet-4-5,claude-sonnet-4-6; effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; schema=strict-004; schema hash=strict-004; parser version=required; refusal field=required; evidence=2026-09-02 | Require a field-level parser probe; HTTP success does not establish parity. | CONDITIONAL — schema probe |
batch54-claude-sonnet-4-5-vs-claude-sonnet-4-6-m1-r5parallel tools | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-sonnet-4-5,claude-sonnet-4-6; effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; tool topology=parallel-005; tool call/result IDs=required; ordering=required; side_effect=read-only; evidence=2026-09-02 | Unavailable — parallel ordering and result association are not evidenced | UNAVAILABLE — tool topology |
batch54-claude-sonnet-4-5-vs-claude-sonnet-4-6-m1-r6computer use | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-sonnet-4-5,claude-sonnet-4-6; effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; computer-use=versioned preview; screenshot/action hashes=required; side_effect=contained; human gate=required; evidence=2026-09-02 | Keep computer-use outside automatic promotion until both exact versions pass the same contained probe. | BLOCKED — high-consequence probe |
First-party provenance: Anthropic Messages API; verification date 2026-09-02. Missing or conflicting joins fail closed.
Behavioral regression evidence ledger
Frozen Batch 54 scenario board. Formula / deterministic rule: regression = matched prompt/config/effort/tools/judge/denominator ∧ comparable result delta; unmatched or anecdotal => no verdict Boundary: This ledger is exact-pair behavioral evidence, not a benchmark rank or universal Claude recommendation.
| Frozen scenario / field ID | Pair, host, surface, and evidence fields | Result | State |
|---|---|---|---|
batch54-claude-sonnet-4-5-vs-claude-sonnet-4-6-m2-r1concise writing | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-sonnet-4-5,claude-sonnet-4-6; effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; cohort=behavior-001; prompt/config/result hashes=paired; rubric=style+factuality; denominator=required; effort=matched; evidence=2026-09-02 | Unavailable — matched observations and denominator are missing | UNTESTED — no comparable run |
batch54-claude-sonnet-4-5-vs-claude-sonnet-4-6-m2-r2instruction hierarchy | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-sonnet-4-5,claude-sonnet-4-6; effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; cohort=behavior-002; prompt hash=behavior-002; system/developer/user layers=paired; judge version=required; evidence=2026-09-02 | Unavailable — layer-specific paired results are absent | UNTESTED — hierarchy evidence |
batch54-claude-sonnet-4-5-vs-claude-sonnet-4-6-m2-r3repository edit | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-sonnet-4-5,claude-sonnet-4-6; effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; cohort=behavior-003; repository/test hashes=paired; tools=paired; patch acceptance=tests+review; attempt cap=2; evidence=2026-09-02 | Unavailable — paired patch outcome is not observed | HOLD — code cohort |
batch54-claude-sonnet-4-5-vs-claude-sonnet-4-6-m2-r4long-conversation recall | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-sonnet-4-5,claude-sonnet-4-6; effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; cohort=behavior-004; conversation hash=recall-004; evidence position=declared; output/citation rubric=required; evidence=2026-09-02 | Unavailable — recall result hashes and support denominator are missing | UNTESTED — recall evidence |
batch54-claude-sonnet-4-5-vs-claude-sonnet-4-6-m2-r5tool selection | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-sonnet-4-5,claude-sonnet-4-6; effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; cohort=behavior-005; tool set/schema/config hashes=paired; selected tool=observed; side_effect=read-only; evidence=2026-09-02 | Unavailable — selection trace is not joined for both versions | UNTESTED — tool evidence |
batch54-claude-sonnet-4-5-vs-claude-sonnet-4-6-m2-r6refusal boundary | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-sonnet-4-5,claude-sonnet-4-6; effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; cohort=behavior-006; prompt hash=behavior-006; policy/version=dated; judge/denominator=required; result hash=missing; evidence=2026-09-02 | Report severity per fixture only; do not make an aggregate upgrade claim from anecdotes. | CONDITIONAL — safety rubric |
First-party provenance: Anthropic Claude model documentation; verification date 2026-09-02. Missing or conflicting joins fail closed.
Adjacent-version rollout and rollback board
Frozen Batch 54 scenario board. Formula / deterministic rule: promote = stage sample floor ∧ acceptance/latency/token gates ∧ pinned fallback ∧ no critical regression; else hold/rollback Boundary: The 4.5 fallback remains available until critical cohorts clear or its lifecycle owner makes it unavailable.
| Frozen scenario / field ID | Pair, host, surface, and evidence fields | Result | State |
|---|---|---|---|
batch54-claude-sonnet-4-5-vs-claude-sonnet-4-6-m3-r11% stage | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-sonnet-4-5,claude-sonnet-4-6; effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; stage=1%; baseline/candidate IDs=pinned; sample floor=declared; cache namespace=isolated; acceptance=required; evidence=2026-09-02 | Unavailable — stage observations are absent | HOLD — 1% untested |
batch54-claude-sonnet-4-5-vs-claude-sonnet-4-6-m3-r210% stage | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-sonnet-4-5,claude-sonnet-4-6; effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; stage=10%; prompt/config hashes=paired; p95/token gates=declared; schema/tool failures=required; fallback=4.5; evidence=2026-09-02 | Unavailable — 10% gate telemetry is not available | HOLD — telemetry missing |
batch54-claude-sonnet-4-5-vs-claude-sonnet-4-6-m3-r350% stage | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-sonnet-4-5,claude-sonnet-4-6; effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; stage=50%; traffic cohort=declared; sample floor=required; critical cohort results=required; alias pinned; evidence=2026-09-02 | Unavailable — critical cohort coverage is missing | HOLD — critical evidence |
batch54-claude-sonnet-4-5-vs-claude-sonnet-4-6-m3-r4full rollout | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-sonnet-4-5,claude-sonnet-4-6; effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; stage=full; rollback ID=claude-sonnet-4-5; cache invalidation=planned; failure threshold=declared; evidence=2026-09-02 | Do not promote to full traffic until every critical gate is joined. | BLOCKED — full gate |
batch54-claude-sonnet-4-5-vs-claude-sonnet-4-6-m3-r5regression stage | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-sonnet-4-5,claude-sonnet-4-6; effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; stage=regression; failure class=required; result hash=required; attempt cap=1; fallback pinned; evidence=2026-09-02 | Rollback to pinned 4.5 on a critical regression and retain the evidence receipt. | ROLLBACK — fallback retained |
batch54-claude-sonnet-4-5-vs-claude-sonnet-4-6-m3-r6alias drift | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider/host/surface=api.anthropic.com / api.anthropic.com; Messages API / Messages API; requested IDs=claude-sonnet-4-5,claude-sonnet-4-6; effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; stage=alias-drift; requested=latest; effective ID=unknown; cache namespace=unknown; source date=dated; evidence=2026-09-02 | Block the stage and repin an exact version; a floating alias cannot hide a contract change. | BLOCKED — alias drift |
First-party provenance: Anthropic Messages API; verification date 2026-09-02. Missing or conflicting joins fail closed.
Method and limitations: formulas are deterministic; assumptions are labeled; no missing provider, host, account, region, realm, cluster, alias, snapshot, version, artifact, effort, tool, modality, benchmark, workload, rate-period, timestamp, or result is transferred. Run the claude-sonnet-4-5-vs-claude-sonnet-4-6 Batch 54 scenario →
Batch 66 · exact-pair decision contributions · verified 2026-09-07
Exact pair boundary: Anthropic; same provider, generational upgrade, identical $3/$15 token pricing, and legacy migration must join. Requested models are claude-sonnet-4-5 and claude-sonnet-4-6. Provider, rate, pricing, and task pages remain fact owners.
Zero-delta migration economic ledger and parity check
Frozen Batch 66 scenario board. Formula / deterministic rule: cost_delta = sonnet_4_6_spend - sonnet_4_5_spend; zero price delta ($3.00/$15.00) Boundary: Owns zero-price-delta migration modeling and workload parity validation.
| Frozen scenario / field ID | Pair, identity, host, surface, and evidence fields | Result | State |
|---|---|---|---|
batch66-claude-sonnet-4-5-vs-claude-sonnet-4-6-m1-r110K coding agent tool calls | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; scenario=10K coding agent tool calls; workload; prompt tokens; completion tokens; Sonnet 4.5 spend; Sonnet 4.6 spend; budget delta; upgrade status; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 10K coding agent tool calls is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch66-claude-sonnet-4-5-vs-claude-sonnet-4-6-m1-r250K automated pull request reviews | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; scenario=50K automated pull request reviews; workload; prompt tokens; completion tokens; Sonnet 4.5 spend; Sonnet 4.6 spend; budget delta; upgrade status; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 50K automated pull request reviews is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch66-claude-sonnet-4-5-vs-claude-sonnet-4-6-m1-r3100K structured data extraction tasks | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; scenario=100K structured data extraction tasks; workload; prompt tokens; completion tokens; Sonnet 4.5 spend; Sonnet 4.6 spend; budget delta; upgrade status; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 100K structured data extraction tasks is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch66-claude-sonnet-4-5-vs-claude-sonnet-4-6-m1-r4prompt caching active (90% read discount both) | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; scenario=prompt caching active (90% read discount both); workload; prompt tokens; completion tokens; Sonnet 4.5 spend; Sonnet 4.6 spend; budget delta; upgrade status; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — prompt caching active (90% read discount both) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch66-claude-sonnet-4-5-vs-claude-sonnet-4-6-m1-r5batch processing active (50% both) | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; scenario=batch processing active (50% both); workload; prompt tokens; completion tokens; Sonnet 4.5 spend; Sonnet 4.6 spend; budget delta; upgrade status; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — batch processing active (50% both) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch66-claude-sonnet-4-5-vs-claude-sonnet-4-6-m1-r6unresolved pricing currency | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; scenario=unresolved pricing currency; workload; prompt tokens; completion tokens; Sonnet 4.5 spend; Sonnet 4.6 spend; budget delta; upgrade status; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — unresolved pricing currency has no matched, dated bilateral observation. | FAIL CLOSED — manual, probe, or source evidence required |
First-party provenance: Anthropic API pricing; verification date 2026-09-07. Missing or conflicting joins fail closed.
Agent tool calling reliability and defect reduction ROI
Frozen Batch 66 scenario board. Formula / deterministic rule: roi = prevented_defects_value - switching_overhead; higher precision justifies cutover Boundary: Owns defect reduction modeling and agent reliability metrics.
| Frozen scenario / field ID | Pair, identity, host, surface, and evidence fields | Result | State |
|---|---|---|---|
batch66-claude-sonnet-4-5-vs-claude-sonnet-4-6-m2-r1autonomous multi-file refactoring | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; scenario=autonomous multi-file refactoring; engineering task; Sonnet 4.5 defect rate; Sonnet 4.6 defect rate; defect reduction; economic ROI; migration recommendation; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — autonomous multi-file refactoring is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch66-claude-sonnet-4-5-vs-claude-sonnet-4-6-m2-r2test suite generation without hallucinated mocks | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; scenario=test suite generation without hallucinated mocks; engineering task; Sonnet 4.5 defect rate; Sonnet 4.6 defect rate; defect reduction; economic ROI; migration recommendation; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — test suite generation without hallucinated mocks is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch66-claude-sonnet-4-5-vs-claude-sonnet-4-6-m2-r3complex JSON schema compliance | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; scenario=complex JSON schema compliance; engineering task; Sonnet 4.5 defect rate; Sonnet 4.6 defect rate; defect reduction; economic ROI; migration recommendation; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — complex JSON schema compliance is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch66-claude-sonnet-4-5-vs-claude-sonnet-4-6-m2-r4external API tool call retry reduction | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; scenario=external API tool call retry reduction; engineering task; Sonnet 4.5 defect rate; Sonnet 4.6 defect rate; defect reduction; economic ROI; migration recommendation; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — external API tool call retry reduction is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch66-claude-sonnet-4-5-vs-claude-sonnet-4-6-m2-r5agent loop runaway circuit breaker | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; scenario=agent loop runaway circuit breaker; engineering task; Sonnet 4.5 defect rate; Sonnet 4.6 defect rate; defect reduction; economic ROI; migration recommendation; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — agent loop runaway circuit breaker is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch66-claude-sonnet-4-5-vs-claude-sonnet-4-6-m2-r6unresolved error penalty metric | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; scenario=unresolved error penalty metric; engineering task; Sonnet 4.5 defect rate; Sonnet 4.6 defect rate; defect reduction; economic ROI; migration recommendation; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — unresolved error penalty metric has no matched, dated bilateral observation. | FAIL CLOSED — manual, probe, or source evidence required |
First-party provenance: Anthropic Claude documentation; verification date 2026-09-07. Missing or conflicting joins fail closed.
Context window saturation (200K parity) and throughput SLA audit
Frozen Batch 66 scenario board. Formula / deterministic rule: turnaround = ttft + (tokens_out / tps); identical 200K context bounds Boundary: Owns turnaround time and throughput verification across versions.
| Frozen scenario / field ID | Pair, identity, host, surface, and evidence fields | Result | State |
|---|---|---|---|
batch66-claude-sonnet-4-5-vs-claude-sonnet-4-6-m3-r1real-time chat autocomplete (<200ms) | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; scenario=real-time chat autocomplete (<200ms); task; response SLA; Sonnet 4.5 turnaround; Sonnet 4.6 turnaround; SLA compliance; responsiveness verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — real-time chat autocomplete (<200ms) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch66-claude-sonnet-4-5-vs-claude-sonnet-4-6-m3-r2complex code refactoring (multi-second OK) | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; scenario=complex code refactoring (multi-second OK); task; response SLA; Sonnet 4.5 turnaround; Sonnet 4.6 turnaround; SLA compliance; responsiveness verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — complex code refactoring (multi-second OK) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch66-claude-sonnet-4-5-vs-claude-sonnet-4-6-m3-r3100K dense documentation analysis | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; scenario=100K dense documentation analysis; task; response SLA; Sonnet 4.5 turnaround; Sonnet 4.6 turnaround; SLA compliance; responsiveness verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 100K dense documentation analysis is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch66-claude-sonnet-4-5-vs-claude-sonnet-4-6-m3-r4200K full context saturation test | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; scenario=200K full context saturation test; task; response SLA; Sonnet 4.5 turnaround; Sonnet 4.6 turnaround; SLA compliance; responsiveness verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 200K full context saturation test is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch66-claude-sonnet-4-5-vs-claude-sonnet-4-6-m3-r5network contention latency buffer | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; scenario=network contention latency buffer; task; response SLA; Sonnet 4.5 turnaround; Sonnet 4.6 turnaround; SLA compliance; responsiveness verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — network contention latency buffer is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch66-claude-sonnet-4-5-vs-claude-sonnet-4-6-m3-r6unmeasured speed fixture | pair=claude-sonnet-4-5 vs claude-sonnet-4-6; provider=Anthropic; hostA=api.anthropic.com; hostB=api.anthropic.com; surfaceA=Anthropic Messages API; surfaceB=Anthropic Messages API; requested/effective IDs=claude-sonnet-4-5,claude-sonnet-4-6; scenario=unmeasured speed fixture; task; response SLA; Sonnet 4.5 turnaround; Sonnet 4.6 turnaround; SLA compliance; responsiveness verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — unmeasured speed fixture is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
First-party provenance: All AI Ask measured speed dataset; verification date 2026-09-07. Missing or conflicting joins fail closed.
Method and limitations: formulas are deterministic; observed and assumed inputs are labeled; no missing provider, host, account, region, realm, alias, snapshot, revision, weight, artifact, control, tool, modality, workload, rate-period, timestamp, or result is transferred. Run the claude-sonnet-4-5-vs-claude-sonnet-4-6 Batch 66 scenario →
How do Claude Sonnet 4.5 and Claude Sonnet 4.6 compare on specs?
| Claude Sonnet 4.5 | Claude Sonnet 4.6 | |
|---|---|---|
| Price (input) | $3.00/M | $3.00/M |
| Price (output) | $15.00/M | $15.00/M |
| Blended price | $6.00/M | $6.00/M |
| Context window | 200,000 tokens | 300,000 tokens ✓ |
| Max output | 32,000 tokens | 64,000 tokens ✓ |
| Modalities | text, vision | text, vision |
| Reasoning mode | Yes | Yes |
| Released | 2025-06 | 2026-03 |
| Speed | Not measured | 76 t/s |
How much do Claude Sonnet 4.5 and Claude Sonnet 4.6 cost at scale?
| Tokens / month | Claude Sonnet 4.5 | Claude Sonnet 4.6 | Delta |
|---|---|---|---|
| 1,000,000 | $6.00 | $6.00 | $0.0000 (1.0×) |
| 10,000,000 | $60.00 | $60.00 | $0.0000 (1.0×) |
| 100,000,000 | $600.00 | $600.00 | $0.0000 (1.0×) |
Choose Claude Sonnet 4.5 if…
- ✓High performance logical reasoning
- ✓Extended thinking mode
- ✓Coding accuracy
- ✓Intermediate Claude 4.5 workflows superseded by Sonnet 4.6.
Choose Claude Sonnet 4.6 if…
- ✓Best intelligence-per-dollar in the Claude lineup
- ✓Fast enough for interactive coding agents
- ✓Reliable structured output
- ✓Enterprise workloads that need Opus-adjacent quality at Sonnet pricing.
Run this exact matchup right now
Send the same prompt to Claude Sonnet 4.5 and Claude Sonnet 4.6 side by side and see the outputs yourself.
Try Claude Sonnet 4.5 vs Claude Sonnet 4.6 FreeWhat are common questions about Claude Sonnet 4.5 and Claude Sonnet 4.6?
Is Claude Sonnet 4.5 cheaper than Claude Sonnet 4.6?
Claude Sonnet 4.5 is cheaper, at $6.00 per million blended tokens vs $6.00 for Claude Sonnet 4.6.
Which has the bigger context window, Claude Sonnet 4.5 or Claude Sonnet 4.6?
Claude Sonnet 4.6 has the larger context window: 300,000 tokens vs 200,000.
Can Claude Sonnet 4.5 replace Claude Sonnet 4.6 for coding?
Both are viable for coding. High performance logical reasoning (Claude Sonnet 4.5) vs Best intelligence-per-dollar in the Claude lineup (Claude Sonnet 4.6) — pick based on which strength matters more for your workload.
Neither of these? See Claude Sonnet 4.6 alternatives.
What related comparisons help choose between Claude Sonnet 4.5 and Claude Sonnet 4.6?
Claude Sonnet 4.5 pricingClaude Sonnet 4.6 pricingvs DeepSeek V4 Provs Claude Sonnet 4vs Claude Opus 4.8vs Claude Sonnet 5Premium model tests
Pricing verified 2026-04-06. Specs verified 2026-08-14.