Compare GPT-4o Mini and GPT-5.6 Luna: Legacy Workhorse to Next-Gen Speed
GPT-4o Mini vs GPT-5.6 Luna: which should I use?
GPT-4o Mini is OpenAI’s previous-generation utility model ($0.15/M input, $0.60/M output), whereas GPT-5.6 Luna brings advanced speculative decoding, higher reasoning capability, and 1M context. Verified 2026-09-07.
Verified 2026-09-07
Where can you find price, speed, and task evidence for GPT-4o Mini and GPT-5.6 Luna?
Which tasks fit GPT-4o Mini and GPT-5.6 Luna?
Best-fit task signals from the published model strengths; this is not a substitute for a controlled benchmark.
| Fact | GPT-4o Mini | GPT-5.6 Luna |
|---|---|---|
| Best fit | Legacy low-cost OpenAI tasks superseded by GPT-5.6 Luna / GPT-5.4 Nano. | High-volume, latency-sensitive tasks like classification, extraction, and chat. |
| Reasoning mode | Unavailable | Unavailable |
What does a Coding Agent workload cost with GPT-4o Mini and GPT-5.6 Luna?
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 | GPT-4o Mini | GPT-5.6 Luna |
|---|---|---|
| Coding Agent / task | $0.0042 (modeled) (winner) | $0.03 (modeled) |
| Input / output rate | $0.15 / $0.60 per M | $1.00 / $6.00 per M |
How fast are GPT-4o Mini and GPT-5.6 Luna?
Only non-estimated benchmark results are shown as measured.
| Fact | GPT-4o Mini | GPT-5.6 Luna |
|---|---|---|
| Measured throughput | Unavailable | 126 tokens/s |
| Time to first token | Unavailable | 300 ms |
How compatible are GPT-4o Mini and GPT-5.6 Luna with APIs?
Provider-level wire-format and SDK facts; model-specific parameter differences may still apply.
| Fact | GPT-4o Mini | GPT-5.6 Luna |
|---|---|---|
| OpenAI SDK | Usable | Usable |
| Request shape | Canonical /chat/completions and /responses shape — every OpenAI-compatible provider on this site imitates it. | Canonical /chat/completions and /responses shape — every OpenAI-compatible provider on this site imitates it. |
| Streaming | SSE (OpenAI delta) | SSE (OpenAI delta) |
What are the privacy and retention policies for GPT-4o Mini and GPT-5.6 Luna?
Provider policy and residency facts from the verified provider registry. A missing retention policy is not treated as a guarantee.
| Fact | GPT-4o Mini | GPT-5.6 Luna |
|---|---|---|
| Provider says API data trains models | No | No |
| Published retention period | Unavailable | Unavailable |
| Data residency | US by default; EU data residency available on enterprise agreements | US by default; EU data residency available on enterprise agreements |
How much effort does it take to migrate between GPT-4o Mini and GPT-5.6 Luna?
Direction is from each displayed model to the other. Effort is derived from provider compatibility and published parameter maps.
| Fact | GPT-4o Mini | GPT-5.6 Luna |
|---|---|---|
| Move GPT-4o Mini → GPT-5.6 Luna | drop-in; 0 breaking parameter differences | Target: GPT-5.6 Luna |
| Move GPT-5.6 Luna → GPT-4o Mini | Source: GPT-5.6 Luna | 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: OpenAI; alias/snapshot=pin each exact model ID; legacy-to-successor mapping is not drop-in. Requested models are gpt-4o-mini and gpt-5.6-luna. Provider, rate, pricing, and task pages remain fact owners.
4o-mini-to-Luna request/response contract compiler
Frozen Batch 54 scenario board. Formula / deterministic rule: cutover = every required semantic mapped ∧ parser/tool/stream probe passes; unknown or dropped required field => block Boundary: Exact pair only: Chat Completions-to-Responses contract change. Model pages retain standalone specifications and migration pages retain tutorials.
| Frozen scenario / field ID | Pair, host, surface, and evidence fields | Result | State |
|---|---|---|---|
batch54-gpt-4o-mini-vs-gpt-5-6-luna-m1-r1plain chat | pair=gpt-4o-mini vs gpt-5.6-luna; provider/host/surface=api.openai.com / api.openai.com; Chat Completions / Responses; requested IDs=gpt-4o-mini,gpt-5.6-luna; effective IDs=gpt-4o-mini,gpt-5.6-luna; alias=none; snapshot=exact; prompt hash=contract-001; response id/output_text mapping=required; usage fields=required; evidence=2026-09-02 | Map messages to input and validate output text plus usage before release. | CONDITIONAL — parser probe required |
batch54-gpt-4o-mini-vs-gpt-5-6-luna-m1-r2image input | pair=gpt-4o-mini vs gpt-5.6-luna; provider/host/surface=api.openai.com / api.openai.com; Chat Completions / Responses; requested IDs=gpt-4o-mini,gpt-5.6-luna; effective IDs=gpt-4o-mini,gpt-5.6-luna; image artifact=img-002; input image hash=img-002; media accounting=required; result hash=missing; evidence=2026-09-02 | Unavailable — media accounting and paired result are not joined | UNAVAILABLE — image contract |
batch54-gpt-4o-mini-vs-gpt-5-6-luna-m1-r3strict JSON | pair=gpt-4o-mini vs gpt-5.6-luna; provider/host/surface=api.openai.com / api.openai.com; Chat Completions / Responses; requested IDs=gpt-4o-mini,gpt-5.6-luna; effective IDs=gpt-4o-mini,gpt-5.6-luna; schema version=strict-003; prompt/config hash=contract-003; schema hash=strict-003; parser=versioned; evidence=2026-09-02 | Transfer only when schema fields and refusal/error handling validate identically. | CONDITIONAL — schema validation |
batch54-gpt-4o-mini-vs-gpt-5-6-luna-m1-r4forced tool | pair=gpt-4o-mini vs gpt-5.6-luna; provider/host/surface=api.openai.com / api.openai.com; Chat Completions / Responses; requested IDs=gpt-4o-mini,gpt-5.6-luna; effective IDs=gpt-4o-mini,gpt-5.6-luna; tool schema=tool-004; tool call/result IDs=required; side_effect=read-only; response field=required; evidence=2026-09-02 | Unavailable — tool event mapping is not evidenced for both surfaces | UNAVAILABLE — tool event join |
batch54-gpt-4o-mini-vs-gpt-5-6-luna-m1-r5parallel tools | pair=gpt-4o-mini vs gpt-5.6-luna; provider/host/surface=api.openai.com / api.openai.com; Chat Completions / Responses; requested IDs=gpt-4o-mini,gpt-5.6-luna; effective IDs=gpt-4o-mini,gpt-5.6-luna; tool topology=parallel-005; tool order and call IDs=required; config hash=contract-005; replay=required; evidence=2026-09-02 | Require per-call association and deterministic replay before enabling parallel calls. | BLOCKED — parallel semantics |
batch54-gpt-4o-mini-vs-gpt-5-6-luna-m1-r6streamed response | pair=gpt-4o-mini vs gpt-5.6-luna; provider/host/surface=api.openai.com / api.openai.com; Chat Completions / Responses; requested IDs=gpt-4o-mini,gpt-5.6-luna; effective IDs=gpt-4o-mini,gpt-5.6-luna; stream version=stream-006; event sequence hash=stream-006; stop/usage fields=required; client parser=versioned; evidence=2026-09-02 | Unavailable — stream event and final usage settlement are missing | UNAVAILABLE — stream probe |
First-party provenance: OpenAI Responses API; verification date 2026-09-02. Missing or conflicting joins fail closed.
Completed-task economics parity receipt
Frozen Batch 54 scenario board. Formula / deterministic rule: accepted cost = Σ(attempt cost) / accepted-result count; no matched acceptance or rate-period join => Unavailable Boundary: This is completed-task parity, not a raw list-price ranking or generic pricing calculator.
| Frozen scenario / field ID | Pair, host, surface, and evidence fields | Result | State |
|---|---|---|---|
batch54-gpt-4o-mini-vs-gpt-5-6-luna-m2-r1classification | pair=gpt-4o-mini vs gpt-5.6-luna; provider/host/surface=api.openai.com / api.openai.com; Responses / Responses; requested IDs=gpt-4o-mini,gpt-5.6-luna; effective IDs=gpt-4o-mini,gpt-5.6-luna; prompt/config hash=econ-001; input/output/reasoning/tool tokens=required; attempts=required; validator denominator=required; evidence=2026-09-02 | Unavailable — accepted-result denominator is not observed for both exact IDs | UNAVAILABLE — no completion parity |
batch54-gpt-4o-mini-vs-gpt-5-6-luna-m2-r2support reply | pair=gpt-4o-mini vs gpt-5.6-luna; provider/host/surface=api.openai.com / api.openai.com; Responses / Responses; requested IDs=gpt-4o-mini,gpt-5.6-luna; effective IDs=gpt-4o-mini,gpt-5.6-luna; prompt/config hash=econ-002; output tokens and human acceptance rubric=required; dated rate owner=linked; evidence=2026-09-02 | Unavailable — matched human acceptance and rate-period join are absent | UNAVAILABLE — acceptance gap |
batch54-gpt-4o-mini-vs-gpt-5-6-luna-m2-r3structured extraction | pair=gpt-4o-mini vs gpt-5.6-luna; provider/host/surface=api.openai.com / api.openai.com; Responses / Responses; requested IDs=gpt-4o-mini,gpt-5.6-luna; effective IDs=gpt-4o-mini,gpt-5.6-luna; schema hash=econ-003; field validator/version=required; attempts and retry tokens=required; result hash=missing; evidence=2026-09-02 | Unavailable — schema yield and retry rate are not measured | UNAVAILABLE — validator yield |
batch54-gpt-4o-mini-vs-gpt-5-6-luna-m2-r4retrieval answer | pair=gpt-4o-mini vs gpt-5.6-luna; provider/host/surface=api.openai.com / api.openai.com; Responses / Responses; requested IDs=gpt-4o-mini,gpt-5.6-luna; effective IDs=gpt-4o-mini,gpt-5.6-luna; prompt/config hash=econ-004; corpus/query hashes=required; citations=required; tool tokens=required; judge denominator=required; evidence=2026-09-02 | Unavailable — paired provenance and accepted-result denominator are missing | UNAVAILABLE — retrieval receipt |
batch54-gpt-4o-mini-vs-gpt-5-6-luna-m2-r5tool lookup | pair=gpt-4o-mini vs gpt-5.6-luna; provider/host/surface=api.openai.com / api.openai.com; Responses / Responses; requested IDs=gpt-4o-mini,gpt-5.6-luna; effective IDs=gpt-4o-mini,gpt-5.6-luna; tool schema=econ-005; tool tokens, attempts, side-effect class, and result validation=required; rate period=dated; evidence=2026-09-02 | Unavailable — tool completion behavior cannot be transferred | UNAVAILABLE — tool economics |
batch54-gpt-4o-mini-vs-gpt-5-6-luna-m2-r6retry after invalid schema | pair=gpt-4o-mini vs gpt-5.6-luna; provider/host/surface=api.openai.com / api.openai.com; Responses / Responses; requested IDs=gpt-4o-mini,gpt-5.6-luna; effective IDs=gpt-4o-mini,gpt-5.6-luna; schema hash=econ-006; attempt cap=2; retry probability=missing; token carry-forward=required; accepted result=required; evidence=2026-09-02 | Apply the formula only after retry probability is measured for this exact workload. | ASSUMPTION ONLY — no cheaper claim |
First-party provenance: OpenAI API pricing; verification date 2026-09-02. Missing or conflicting joins fail closed.
Low-cost-default shadow and rollback board
Frozen Batch 54 scenario board. Formula / deterministic rule: promote = sample floor ∧ acceptance/latency gates ∧ cache isolation ∧ critical cohorts clear; else keep baseline Boundary: Shadow observations cannot authorize side effects or replace the 4o mini fallback without workload-owned evidence.
| Frozen scenario / field ID | Pair, host, surface, and evidence fields | Result | State |
|---|---|---|---|
batch54-gpt-4o-mini-vs-gpt-5-6-luna-m3-r1read-only chat | pair=gpt-4o-mini vs gpt-5.6-luna; provider/host/surface=api.openai.com / api.openai.com; Responses / Responses; requested IDs=gpt-4o-mini,gpt-5.6-luna; effective IDs=gpt-4o-mini,gpt-5.6-luna; cohort=shadow-001; sample floor=declared; prompt/config hashes=paired; side_effect=none; baseline/candidate=exact; evidence=2026-09-02 | Unavailable — sample and paired acceptance observations are absent | HOLD — shadow untested |
batch54-gpt-4o-mini-vs-gpt-5-6-luna-m3-r2schema workload | pair=gpt-4o-mini vs gpt-5.6-luna; provider/host/surface=api.openai.com / api.openai.com; Responses / Responses; requested IDs=gpt-4o-mini,gpt-5.6-luna; effective IDs=gpt-4o-mini,gpt-5.6-luna; cohort=shadow-002; schema hash=paired; validator denominator=required; cache namespace=isolated; attempt cap=2; evidence=2026-09-02 | Unavailable — schema failure gate is not observed | HOLD — schema gate |
batch54-gpt-4o-mini-vs-gpt-5-6-luna-m3-r3tool agent | pair=gpt-4o-mini vs gpt-5.6-luna; provider/host/surface=api.openai.com / api.openai.com; Responses / Responses; requested IDs=gpt-4o-mini,gpt-5.6-luna; effective IDs=gpt-4o-mini,gpt-5.6-luna; cohort=shadow-003; tool trace hash=required; read-only effects; rollback target=gpt-4o-mini; sample floor=declared; evidence=2026-09-02 | Do not promote while tool traces or rollback artifacts are missing. | BLOCKED — tool evidence |
batch54-gpt-4o-mini-vs-gpt-5-6-luna-m3-r4image workflow | pair=gpt-4o-mini vs gpt-5.6-luna; provider/host/surface=api.openai.com / api.openai.com; Responses / Responses; requested IDs=gpt-4o-mini,gpt-5.6-luna; effective IDs=gpt-4o-mini,gpt-5.6-luna; cohort=shadow-004; image artifact hashes=paired; media accounting=required; quality rubric=required; cache=isolated; evidence=2026-09-02 | Unavailable — paired image acceptance is not available | HOLD — media cohort |
batch54-gpt-4o-mini-vs-gpt-5-6-luna-m3-r5latency regression | pair=gpt-4o-mini vs gpt-5.6-luna; provider/host/surface=api.openai.com / api.openai.com; Responses / Responses; requested IDs=gpt-4o-mini,gpt-5.6-luna; effective IDs=gpt-4o-mini,gpt-5.6-luna; cohort=shadow-005; p50/p95=measurement required; same region and prompt hashes; SLO=declared; evidence=2026-09-02 | Unavailable — latency is not measured for this matched cohort | UNAVAILABLE — latency join |
batch54-gpt-4o-mini-vs-gpt-5-6-luna-m3-r6repeated failure | pair=gpt-4o-mini vs gpt-5.6-luna; provider/host/surface=api.openai.com / api.openai.com; Responses / Responses; requested IDs=gpt-4o-mini,gpt-5.6-luna; effective IDs=gpt-4o-mini,gpt-5.6-luna; cohort=shadow-006; attempt cap=2; failure class=required; idempotency=required; baseline fallback=ready; evidence=2026-09-02 | Stop after the cap, settle effects, and route to human review before retrying. | ROLLBACK — bounded failure |
First-party provenance: OpenAI model documentation; 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 gpt-4o-mini-vs-gpt-5-6-luna Batch 54 scenario →
Batch 64 · exact-pair decision contributions · verified 2026-09-07
Exact pair boundary: OpenAI; same provider, legacy utility model vs next-generation lightweight flagship, and migration break-even must join. Requested models are gpt-4o-mini and gpt-5.6-luna. Provider, rate, pricing, and task pages remain fact owners.
Legacy maintenance vs Luna upgrade migration ledger
Frozen Batch 64 scenario board. Formula / deterministic rule: migration_delta = luna_monthly_spend - mini_monthly_spend; quality gain justifies cost Boundary: Owns upgrade decision modeling from GPT-4o Mini to GPT-5.6 Luna.
| Frozen scenario / field ID | Pair, identity, host, surface, and evidence fields | Result | State |
|---|---|---|---|
batch64-gpt-4o-mini-vs-gpt-5-6-luna-m1-r110K interactive chat queries | pair=gpt-4o-mini vs gpt-5.6-luna; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-4o-mini,gpt-5.6-luna; scenario=10K interactive chat queries; workload volume; GPT-4o Mini spend; GPT-5.6 Luna spend; budget delta; defect reduction requirement; upgrade status; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 10K interactive chat queries is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch64-gpt-4o-mini-vs-gpt-5-6-luna-m1-r250K data extraction tasks | pair=gpt-4o-mini vs gpt-5.6-luna; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-4o-mini,gpt-5.6-luna; scenario=50K data extraction tasks; workload volume; GPT-4o Mini spend; GPT-5.6 Luna spend; budget delta; defect reduction requirement; upgrade status; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 50K data extraction tasks is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch64-gpt-4o-mini-vs-gpt-5-6-luna-m1-r3100K classification events | pair=gpt-4o-mini vs gpt-5.6-luna; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-4o-mini,gpt-5.6-luna; scenario=100K classification events; workload volume; GPT-4o Mini spend; GPT-5.6 Luna spend; budget delta; defect reduction requirement; upgrade status; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 100K classification events is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch64-gpt-4o-mini-vs-gpt-5-6-luna-m1-r4500K high-volume customer queries | pair=gpt-4o-mini vs gpt-5.6-luna; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-4o-mini,gpt-5.6-luna; scenario=500K high-volume customer queries; workload volume; GPT-4o Mini spend; GPT-5.6 Luna spend; budget delta; defect reduction requirement; upgrade status; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 500K high-volume customer queries is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch64-gpt-4o-mini-vs-gpt-5-6-luna-m1-r5batch queue workload (50% discount) | pair=gpt-4o-mini vs gpt-5.6-luna; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-4o-mini,gpt-5.6-luna; scenario=batch queue workload (50% discount); workload volume; GPT-4o Mini spend; GPT-5.6 Luna spend; budget delta; defect reduction requirement; upgrade status; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — batch queue workload (50% discount) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch64-gpt-4o-mini-vs-gpt-5-6-luna-m1-r6unresolved parameter mapping | pair=gpt-4o-mini vs gpt-5.6-luna; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-4o-mini,gpt-5.6-luna; scenario=unresolved parameter mapping; workload volume; GPT-4o Mini spend; GPT-5.6 Luna spend; budget delta; defect reduction requirement; upgrade status; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — unresolved parameter mapping has no matched, dated bilateral observation. | FAIL CLOSED — manual, probe, or source evidence required |
First-party provenance: OpenAI API pricing; verification date 2026-09-07. Missing or conflicting joins fail closed.
Sub-second turnaround and speculative decoding throughput
Frozen Batch 64 scenario board. Formula / deterministic rule: latency_gain = mini_turnaround - luna_turnaround; speculative decoding enhances Luna Boundary: Owns speed benchmarks and interactive user experience benefits.
| Frozen scenario / field ID | Pair, identity, host, surface, and evidence fields | Result | State |
|---|---|---|---|
batch64-gpt-4o-mini-vs-gpt-5-6-luna-m2-r1real-time conversational response (<300ms) | pair=gpt-4o-mini vs gpt-5.6-luna; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-4o-mini,gpt-5.6-luna; scenario=real-time conversational response (<300ms); task; response SLA; Mini latency; Luna latency; latency improvement; responsiveness winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — real-time conversational response (<300ms) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch64-gpt-4o-mini-vs-gpt-5-6-luna-m2-r2automated code snippet generation | pair=gpt-4o-mini vs gpt-5.6-luna; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-4o-mini,gpt-5.6-luna; scenario=automated code snippet generation; task; response SLA; Mini latency; Luna latency; latency improvement; responsiveness winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — automated code snippet generation is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch64-gpt-4o-mini-vs-gpt-5-6-luna-m2-r3streaming classification event | pair=gpt-4o-mini vs gpt-5.6-luna; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-4o-mini,gpt-5.6-luna; scenario=streaming classification event; task; response SLA; Mini latency; Luna latency; latency improvement; responsiveness winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — streaming classification event is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch64-gpt-4o-mini-vs-gpt-5-6-luna-m2-r4high-concurrency request surge | pair=gpt-4o-mini vs gpt-5.6-luna; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-4o-mini,gpt-5.6-luna; scenario=high-concurrency request surge; task; response SLA; Mini latency; Luna latency; latency improvement; responsiveness winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — high-concurrency request surge is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch64-gpt-4o-mini-vs-gpt-5-6-luna-m2-r5rate limit throttling buffer | pair=gpt-4o-mini vs gpt-5.6-luna; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-4o-mini,gpt-5.6-luna; scenario=rate limit throttling buffer; task; response SLA; Mini latency; Luna latency; latency improvement; responsiveness winner; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — rate limit throttling buffer is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch64-gpt-4o-mini-vs-gpt-5-6-luna-m2-r6unmeasured speed fixture | pair=gpt-4o-mini vs gpt-5.6-luna; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-4o-mini,gpt-5.6-luna; scenario=unmeasured speed fixture; task; response SLA; Mini latency; Luna latency; latency improvement; responsiveness winner; 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.
Context window expansion (128K vs 1M) workload gate
Frozen Batch 64 scenario board. Formula / deterministic rule: eligible = (context <= 128K ? Both : (context <= 1M ? Luna : Excluded)) Boundary: Owns context scaling and capability gating for large inputs.
| Frozen scenario / field ID | Pair, identity, host, surface, and evidence fields | Result | State |
|---|---|---|---|
batch64-gpt-4o-mini-vs-gpt-5-6-luna-m3-r1standard prompt (10K tokens) | pair=gpt-4o-mini vs gpt-5.6-luna; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-4o-mini,gpt-5.6-luna; scenario=standard prompt (10K tokens); context size; Mini eligible; Luna eligible; Mini cost; Luna cost; workload gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — standard prompt (10K tokens) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch64-gpt-4o-mini-vs-gpt-5-6-luna-m3-r2large document (64K tokens) | pair=gpt-4o-mini vs gpt-5.6-luna; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-4o-mini,gpt-5.6-luna; scenario=large document (64K tokens); context size; Mini eligible; Luna eligible; Mini cost; Luna cost; workload gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — large document (64K tokens) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch64-gpt-4o-mini-vs-gpt-5-6-luna-m3-r3maximum Mini context (128K boundary) | pair=gpt-4o-mini vs gpt-5.6-luna; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-4o-mini,gpt-5.6-luna; scenario=maximum Mini context (128K boundary); context size; Mini eligible; Luna eligible; Mini cost; Luna cost; workload gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — maximum Mini context (128K boundary) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch64-gpt-4o-mini-vs-gpt-5-6-luna-m3-r4repository dump (250K tokens) | pair=gpt-4o-mini vs gpt-5.6-luna; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-4o-mini,gpt-5.6-luna; scenario=repository dump (250K tokens); context size; Mini eligible; Luna eligible; Mini cost; Luna cost; workload gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — repository dump (250K tokens) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch64-gpt-4o-mini-vs-gpt-5-6-luna-m3-r51M full context analysis | pair=gpt-4o-mini vs gpt-5.6-luna; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-4o-mini,gpt-5.6-luna; scenario=1M full context analysis; context size; Mini eligible; Luna eligible; Mini cost; Luna cost; workload gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 1M full context analysis is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch64-gpt-4o-mini-vs-gpt-5-6-luna-m3-r6unsupported context request | pair=gpt-4o-mini vs gpt-5.6-luna; provider=OpenAI; hostA=api.openai.com; hostB=api.openai.com; surfaceA=OpenAI Responses API; surfaceB=OpenAI Responses API; requested/effective IDs=gpt-4o-mini,gpt-5.6-luna; scenario=unsupported context request; context size; Mini eligible; Luna eligible; Mini cost; Luna cost; workload gate verdict; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — unsupported context request has no matched, dated bilateral observation. | FAIL CLOSED — manual, probe, or source evidence required |
First-party provenance: OpenAI model documentation; 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 gpt-4o-mini-vs-gpt-5-6-luna Batch 64 scenario →
How do GPT-4o Mini and GPT-5.6 Luna compare on specs?
| GPT-4o Mini | GPT-5.6 Luna | |
|---|---|---|
| Price (input) | $0.15/M ✓ | $1.00/M |
| Price (output) | $0.60/M ✓ | $6.00/M |
| Blended price | $0.26/M ✓ | $2.25/M |
| Context window | 128,000 tokens | 1,000,000 tokens ✓ |
| Max output | 16,384 tokens | 64,000 tokens ✓ |
| Modalities | text, vision | text, vision |
| Reasoning mode | No | No |
| Released | 2024-07 | 2026-06 |
| Speed | Not measured | 126 t/s |
How much do GPT-4o Mini and GPT-5.6 Luna cost at scale?
| Tokens / month | GPT-4o Mini | GPT-5.6 Luna | Delta |
|---|---|---|---|
| 1,000,000 | $0.26 | $2.25 | $1.99 (8.6×) |
| 10,000,000 | $2.62 | $22.50 | $19.88 (8.6×) |
| 100,000,000 | $26.25 | $225.00 | $198.75 (8.6×) |
Choose GPT-4o Mini if…
- ✓Lightweight and cost-effective
- ✓Fast response time
- ✓Vision support
- ✓Legacy low-cost OpenAI tasks superseded by GPT-5.6 Luna / GPT-5.4 Nano.
Choose GPT-5.6 Luna if…
- ✓Cheapest current GPT-5.6 tier
- ✓Low latency for high-volume calls
- ✓1M context window and vision input
- ✓High-volume, latency-sensitive tasks like classification, extraction, and chat.
Run this exact matchup right now
Send the same prompt to GPT-4o Mini and GPT-5.6 Luna side by side and see the outputs yourself.
Try GPT-4o Mini vs GPT-5.6 Luna FreeWhat are common questions about GPT-4o Mini and GPT-5.6 Luna?
Is GPT-4o Mini cheaper than GPT-5.6 Luna?
GPT-4o Mini is cheaper, at $0.26 per million blended tokens vs $2.25 for GPT-5.6 Luna.
Which has the bigger context window, GPT-4o Mini or GPT-5.6 Luna?
GPT-5.6 Luna has the larger context window: 1,000,000 tokens vs 128,000.
Can GPT-4o Mini replace GPT-5.6 Luna for coding?
Both are viable for coding. Lightweight and cost-effective (GPT-4o Mini) vs Cheapest current GPT-5.6 tier (GPT-5.6 Luna) — pick based on which strength matters more for your workload.
Neither of these? See GPT-5.6 Luna alternatives.
What related comparisons help choose between GPT-4o Mini and GPT-5.6 Luna?
Pricing verified 2026-04-06. Specs verified 2026-08-14.