Compare Grok 3 and Grok 4.3 migration risks and output headroom
Grok-3 vs Grok 4.3: which should I use?
Migrate from Grok 3 to Grok 4.3 by testing the 8K to 64K output expansion, evaluating token rate differences, and controlling reasoning mode overhead. Verified 2026-09-07; unmeasured legacy speed and undocumented endpoints remain Unavailable.
Where can you find price, speed, and task evidence for Grok-3 and Grok 4.3?
Which tasks fit Grok-3 and Grok 4.3?
Best-fit task signals from the published model strengths; this is not a substitute for a controlled benchmark.
| Fact | Grok-3 | Grok 4.3 |
|---|---|---|
| Best fit | Legacy Grok workloads superseded by Grok 4.3. | General-purpose work where speed and a huge context window both matter. |
| Reasoning mode | Unavailable | Available |
What does a Coding Agent workload cost with Grok-3 and Grok 4.3?
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 | Grok-3 | Grok 4.3 |
|---|---|---|
| Coding Agent / task | $0.05 (modeled) | $0.03 (modeled) (winner) |
| Input / output rate | $2.00 / $4.00 per M | $1.25 / $2.50 per M |
How fast are Grok-3 and Grok 4.3?
Only non-estimated benchmark results are shown as measured.
| Fact | Grok-3 | Grok 4.3 |
|---|---|---|
| Measured throughput | Unavailable | 98 tokens/s |
| Time to first token | Unavailable | 320 ms |
How compatible are Grok-3 and Grok 4.3 with APIs?
Provider-level wire-format and SDK facts; model-specific parameter differences may still apply.
| Fact | Grok-3 | Grok 4.3 |
|---|---|---|
| OpenAI SDK | Usable | Usable |
| Request shape | Full OpenAI chat/completions compatibility — point the openai SDK at api.x.ai and it works unmodified. | Full OpenAI chat/completions compatibility — point the openai SDK at api.x.ai and it works unmodified. |
| Streaming | SSE (OpenAI delta) | SSE (OpenAI delta) |
What are the privacy and retention policies for Grok-3 and Grok 4.3?
Provider policy and residency facts from the verified provider registry. A missing retention policy is not treated as a guarantee.
| Fact | Grok-3 | Grok 4.3 |
|---|---|---|
| Provider says API data trains models | Unavailable | Unavailable |
| Published retention period | Unavailable | Unavailable |
| Data residency | Unavailable | Unavailable |
How much effort does it take to migrate between Grok-3 and Grok 4.3?
Direction is from each displayed model to the other. Effort is derived from provider compatibility and published parameter maps.
| Fact | Grok-3 | Grok 4.3 |
|---|---|---|
| Move Grok-3 → Grok 4.3 | drop-in; 0 breaking parameter differences | Target: Grok 4.3 |
| Move Grok 4.3 → Grok-3 | Source: Grok 4.3 | drop-in; 0 breaking parameter differences |
| Why | Same provider; only the model identifier changes. | Same provider; only the model identifier changes. |
Grok-3 vs Grok 4.3 1M-context output-headroom planner
Formula: headroom = maxOutput − requested output; fit = input ≤ contextWindow AND output ≤ maxOutput. Chat, document, and long-generation shapes are explicit; truncation risk is not quality.
| Workload shape | Grok-3 | Grok 4.3 |
|---|---|---|
| Chat: 1,000 in / 2,000 out | headroom 6,192; Eligible; truncation none | headroom 62,000; Eligible; truncation none |
| Document: 800,000 in / 8,000 out | headroom 192; Eligible; truncation none | headroom 56,000; Eligible; truncation none |
| Long generation: 100,000 in / 64,000 out | headroom -55,808; Excluded; truncation risk | headroom 0; Eligible; truncation none |
Verified 2026-04-06. Pricing provenance: Grok-3 pricing (2026-04-06); Grok 4.3 pricing (2026-05-19). Capability: Grok-3; Grok 4.3. Provider: xAI; xAI. Missing evidence is Unavailable, never inferred.
Grok-3 vs Grok 4.3 same-volume migration bill
Formula: same-volume bill = (100,000 × input $/M + 8,000 × output $/M) / 1,000,000; equal-cost retry rate is solved from A = B × (1+r), not guessed.
| Calculation | Grok-3 | Grok 4.3 |
|---|---|---|
| Rates + provenance | $2.000000 input / $4.000000 output per M (standard/peak); pricing sourceUrl | $1.250000 input / $2.500000 output per M (standard/peak); pricing sourceUrl |
| 100,000 input + 8,000 output | $0.232000 | $0.145000 |
| Derived metric | Grok-3 | Grok 4.3 |
|---|---|---|
| Bill per call | $0.232000 | $0.145000 |
| Retry rate before equal cost | 0.600× | baseline |
| Observed speed / TTFT | Unavailable | 98 tokens/s; TTFT 320 ms; p95 82.32 tokens/s; n=5 |
There is no Grok 3 measured speed row in SPEED_DATA; therefore no speedup claim is made.
Verified 2026-04-06. Pricing provenance: Grok-3 pricing (2026-04-06); Grok 4.3 pricing (2026-05-19). Capability: Grok-3; Grok 4.3. Provider: xAI; xAI. Missing evidence is Unavailable, never inferred.
Grok-3 vs Grok 4.3 reasoning-mode adoption canary
Formula: canary bill = calls × [(input × input $/M) + (output × output $/M)] / 1,000,000. Success, latency and stop limits are user-supplied.
| Output expansion | Grok-3 | Grok 4.3 |
|---|---|---|
| 1× output (4,000 × 1) | $0.056000 | $0.035000 |
| 2× output (4,000 × 2) | $0.072000 | $0.045000 |
| 4× output (4,000 × 4) | $0.104000 | $0.065000 |
| Stop rules | User: cost + truncation + legacy-evidence thresholds | User: cost + truncation + legacy-evidence thresholds |
Verified 2026-04-06. Pricing provenance: Grok-3 pricing (2026-04-06); Grok 4.3 pricing (2026-05-19). Capability: Grok-3; Grok 4.3. Provider: xAI; xAI. Missing evidence is Unavailable, never inferred.
Batch 60 · exact-pair decision contributions · verified 2026-09-07
Exact pair boundary: xAI; model endpoint identifier, output headroom, token billing rates, and reasoning parameters must join. Requested models are grok-3 and grok-4.3. Provider, rate, pricing, and task pages remain fact owners.
Output-headroom and truncation risk planner
Frozen Batch 60 scenario board. Formula / deterministic rule: headroom = max_output_grok43 - max_output_grok3; truncation_risk = request_tokens > 8192 ? High : Low Boundary: Owns output length expansion modeling; provider profile owns platform limits.
| Frozen scenario / field ID | Pair, identity, host, surface, and evidence fields | Result | State |
|---|---|---|---|
batch60-grok-3-vs-grok-4-3-m1-r1short chat response (<2K) | pair=grok-3 vs grok-4.3; provider=xAI; hostA=api.x.ai; hostB=api.x.ai; surfaceA=xAI API (legacy); surfaceB=xAI API; requested/effective IDs=grok-3,grok-4.3; scenario=short chat response (<2K); request type; target output tokens; Grok 3 limit; Grok 4.3 limit; truncation risk; mitigation action; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — short chat response (<2K) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch60-grok-3-vs-grok-4-3-m1-r2standard generation (4K) | pair=grok-3 vs grok-4.3; provider=xAI; hostA=api.x.ai; hostB=api.x.ai; surfaceA=xAI API (legacy); surfaceB=xAI API; requested/effective IDs=grok-3,grok-4.3; scenario=standard generation (4K); request type; target output tokens; Grok 3 limit; Grok 4.3 limit; truncation risk; mitigation action; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — standard generation (4K) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch60-grok-3-vs-grok-4-3-m1-r3code file creation (8K boundary) | pair=grok-3 vs grok-4.3; provider=xAI; hostA=api.x.ai; hostB=api.x.ai; surfaceA=xAI API (legacy); surfaceB=xAI API; requested/effective IDs=grok-3,grok-4.3; scenario=code file creation (8K boundary); request type; target output tokens; Grok 3 limit; Grok 4.3 limit; truncation risk; mitigation action; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — code file creation (8K boundary) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch60-grok-3-vs-grok-4-3-m1-r4long document draft (16K) | pair=grok-3 vs grok-4.3; provider=xAI; hostA=api.x.ai; hostB=api.x.ai; surfaceA=xAI API (legacy); surfaceB=xAI API; requested/effective IDs=grok-3,grok-4.3; scenario=long document draft (16K); request type; target output tokens; Grok 3 limit; Grok 4.3 limit; truncation risk; mitigation action; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — long document draft (16K) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch60-grok-3-vs-grok-4-3-m1-r5deep reasoning output (64K) | pair=grok-3 vs grok-4.3; provider=xAI; hostA=api.x.ai; hostB=api.x.ai; surfaceA=xAI API (legacy); surfaceB=xAI API; requested/effective IDs=grok-3,grok-4.3; scenario=deep reasoning output (64K); request type; target output tokens; Grok 3 limit; Grok 4.3 limit; truncation risk; mitigation action; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — deep reasoning output (64K) is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch60-grok-3-vs-grok-4-3-m1-r6unsupported output size | pair=grok-3 vs grok-4.3; provider=xAI; hostA=api.x.ai; hostB=api.x.ai; surfaceA=xAI API (legacy); surfaceB=xAI API; requested/effective IDs=grok-3,grok-4.3; scenario=unsupported output size; request type; target output tokens; Grok 3 limit; Grok 4.3 limit; truncation risk; mitigation action; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — unsupported output size has no matched, dated bilateral observation. | FAIL CLOSED — manual, probe, or source evidence required |
First-party provenance: xAI model documentation; verification date 2026-09-07. Missing or conflicting joins fail closed.
Same-volume migration bill and retry tolerance
Frozen Batch 60 scenario board. Formula / deterministic rule: monthly_delta = monthly_calls * (token_delta_cost); max_retry_rate = cost_headroom / single_call_cost Boundary: Owns token bill transition analysis; standalone pricing pages own exact tariffs.
| Frozen scenario / field ID | Pair, identity, host, surface, and evidence fields | Result | State |
|---|---|---|---|
batch60-grok-3-vs-grok-4-3-m2-r110K monthly calls | pair=grok-3 vs grok-4.3; provider=xAI; hostA=api.x.ai; hostB=api.x.ai; surfaceA=xAI API (legacy); surfaceB=xAI API; requested/effective IDs=grok-3,grok-4.3; scenario=10K monthly calls; call volume; average prompt tokens; average completion tokens; Grok 3 cost; Grok 4.3 cost; cost ratio; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 10K monthly calls is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch60-grok-3-vs-grok-4-3-m2-r250K monthly calls | pair=grok-3 vs grok-4.3; provider=xAI; hostA=api.x.ai; hostB=api.x.ai; surfaceA=xAI API (legacy); surfaceB=xAI API; requested/effective IDs=grok-3,grok-4.3; scenario=50K monthly calls; call volume; average prompt tokens; average completion tokens; Grok 3 cost; Grok 4.3 cost; cost ratio; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 50K monthly calls is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch60-grok-3-vs-grok-4-3-m2-r3250K production traffic | pair=grok-3 vs grok-4.3; provider=xAI; hostA=api.x.ai; hostB=api.x.ai; surfaceA=xAI API (legacy); surfaceB=xAI API; requested/effective IDs=grok-3,grok-4.3; scenario=250K production traffic; call volume; average prompt tokens; average completion tokens; Grok 3 cost; Grok 4.3 cost; cost ratio; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 250K production traffic is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch60-grok-3-vs-grok-4-3-m2-r41M enterprise workload | pair=grok-3 vs grok-4.3; provider=xAI; hostA=api.x.ai; hostB=api.x.ai; surfaceA=xAI API (legacy); surfaceB=xAI API; requested/effective IDs=grok-3,grok-4.3; scenario=1M enterprise workload; call volume; average prompt tokens; average completion tokens; Grok 3 cost; Grok 4.3 cost; cost ratio; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 1M enterprise workload is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch60-grok-3-vs-grok-4-3-m2-r5high-retry scenario | pair=grok-3 vs grok-4.3; provider=xAI; hostA=api.x.ai; hostB=api.x.ai; surfaceA=xAI API (legacy); surfaceB=xAI API; requested/effective IDs=grok-3,grok-4.3; scenario=high-retry scenario; call volume; average prompt tokens; average completion tokens; Grok 3 cost; Grok 4.3 cost; cost ratio; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — high-retry scenario is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch60-grok-3-vs-grok-4-3-m2-r6unresolved token count | pair=grok-3 vs grok-4.3; provider=xAI; hostA=api.x.ai; hostB=api.x.ai; surfaceA=xAI API (legacy); surfaceB=xAI API; requested/effective IDs=grok-3,grok-4.3; scenario=unresolved token count; call volume; average prompt tokens; average completion tokens; Grok 3 cost; Grok 4.3 cost; cost ratio; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — unresolved token count has no matched, dated bilateral observation. | FAIL CLOSED — manual, probe, or source evidence required |
First-party provenance: xAI API pricing documentation; verification date 2026-09-07. Missing or conflicting joins fail closed.
Reasoning-mode adoption canary and safety board
Frozen Batch 60 scenario board. Formula / deterministic rule: adopt = error_rate_drop > reasoning_cost_multiplier && latency < sla_limit; missing speed sample => Untested Boundary: Owns canary gates for activating reasoning parameters.
| Frozen scenario / field ID | Pair, identity, host, surface, and evidence fields | Result | State |
|---|---|---|---|
batch60-grok-3-vs-grok-4-3-m3-r11x standard output | pair=grok-3 vs grok-4.3; provider=xAI; hostA=api.x.ai; hostB=api.x.ai; surfaceA=xAI API (legacy); surfaceB=xAI API; requested/effective IDs=grok-3,grok-4.3; scenario=1x standard output; reasoning effort; token expansion; latency delta; error reduction requirement; adoption gate; status; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 1x standard output is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch60-grok-3-vs-grok-4-3-m3-r22x moderate thinking | pair=grok-3 vs grok-4.3; provider=xAI; hostA=api.x.ai; hostB=api.x.ai; surfaceA=xAI API (legacy); surfaceB=xAI API; requested/effective IDs=grok-3,grok-4.3; scenario=2x moderate thinking; reasoning effort; token expansion; latency delta; error reduction requirement; adoption gate; status; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 2x moderate thinking is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch60-grok-3-vs-grok-4-3-m3-r34x deep reasoning | pair=grok-3 vs grok-4.3; provider=xAI; hostA=api.x.ai; hostB=api.x.ai; surfaceA=xAI API (legacy); surfaceB=xAI API; requested/effective IDs=grok-3,grok-4.3; scenario=4x deep reasoning; reasoning effort; token expansion; latency delta; error reduction requirement; adoption gate; status; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — 4x deep reasoning is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch60-grok-3-vs-grok-4-3-m3-r4latency SLA breach | pair=grok-3 vs grok-4.3; provider=xAI; hostA=api.x.ai; hostB=api.x.ai; surfaceA=xAI API (legacy); surfaceB=xAI API; requested/effective IDs=grok-3,grok-4.3; scenario=latency SLA breach; reasoning effort; token expansion; latency delta; error reduction requirement; adoption gate; status; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — latency SLA breach is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch60-grok-3-vs-grok-4-3-m3-r5budget limit reached | pair=grok-3 vs grok-4.3; provider=xAI; hostA=api.x.ai; hostB=api.x.ai; surfaceA=xAI API (legacy); surfaceB=xAI API; requested/effective IDs=grok-3,grok-4.3; scenario=budget limit reached; reasoning effort; token expansion; latency delta; error reduction requirement; adoption gate; status; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — budget limit reached is a frozen fixture pending exact identity, configuration, and denominator joins. | UNTESTED — assumption cannot establish a verdict |
batch60-grok-3-vs-grok-4-3-m3-r6missing legacy speed run | pair=grok-3 vs grok-4.3; provider=xAI; hostA=api.x.ai; hostB=api.x.ai; surfaceA=xAI API (legacy); surfaceB=xAI API; requested/effective IDs=grok-3,grok-4.3; scenario=missing legacy speed run; reasoning effort; token expansion; latency delta; error reduction requirement; adoption gate; status; prompt/config/input/output/result/cache/checkpoint/artifact hashes=required; evidence=2026-09-07; measurement versus assumption=explicit | Unavailable — missing legacy speed run has no matched, dated bilateral observation. | FAIL CLOSED — manual, probe, or source evidence required |
First-party provenance: xAI API 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 grok-3-vs-grok-4-3 Batch 60 scenario →
How do Grok-3 and Grok 4.3 compare on specs?
| Grok-3 | Grok 4.3 | |
|---|---|---|
| Price (input) | $2.00/M | $1.25/M ✓ |
| Price (output) | $4.00/M | $2.50/M ✓ |
| Blended price | $2.50/M | $1.56/M ✓ |
| Context window | 1,000,000 tokens | 1,000,000 tokens |
| Max output | 8,192 tokens | 64,000 tokens ✓ |
| Modalities | text, vision | text, vision |
| Reasoning mode | No | Yes |
| Released | 2025-02 | 2026-06 |
| Speed | Not measured | 98 t/s |
How much do Grok-3 and Grok 4.3 cost at scale?
| Tokens / month | Grok-3 | Grok 4.3 | Delta |
|---|---|---|---|
| 1,000,000 | $2.50 | $1.56 | $0.94 (1.6×) |
| 10,000,000 | $25.00 | $15.63 | $9.38 (1.6×) |
| 100,000,000 | $250.00 | $156.25 | $93.75 (1.6×) |
Choose Grok-3 if…
- ✓Classic Grok flagship
- ✓1M context window
- ✓Document analysis
- ✓Legacy Grok workloads superseded by Grok 4.3.
Choose Grok 4.3 if…
- ✓xAI’s general-purpose flagship
- ✓Extremely fast for its size
- ✓1M-token context
- ✓General-purpose work where speed and a huge context window both matter.
Run this exact matchup right now
Send the same prompt to Grok-3 and Grok 4.3 side by side and see the outputs yourself.
Try Grok-3 vs Grok 4.3 FreeWhat are common questions about Grok-3 and Grok 4.3?
Is Grok-3 cheaper than Grok 4.3?
Grok 4.3 is cheaper, at $1.56 per million blended tokens vs $2.50 for Grok-3.
Which has the bigger context window, Grok-3 or Grok 4.3?
Both models support 1,000,000 tokens of context.
Can Grok-3 replace Grok 4.3 for coding?
Both are viable for coding. Classic Grok flagship (Grok-3) vs xAI’s general-purpose flagship (Grok 4.3) — pick based on which strength matters more for your workload.
Neither of these? See Grok 4.3 alternatives.
What related comparisons help choose between Grok-3 and Grok 4.3?
Pricing verified 2026-04-06. Specs verified 2026-08-14.