GPT-5.1 vs Grok 4.3
At a Glance
| Compare |  GPT-5.1OpenAI | Grok 4.3xAI |
|---|---|---|
| Intelligence, Cost, and Efficiency | ||
| IntelligenceHigher is better · MM Intelligence v2.5 | #37 of 4625.7 score · 2/3 sources · provisional · missing LiveBench · full-core range 17.1–50.5 | #40 of 4616.6 score · 2/3 sources · provisional · missing ARC-AGI-2 · full-core range 11.1–44.4 |
| CostLower is better · Published-token output estimate | UnrankedNot in the 44-model eligible cohort | #7 of 44$0.028 per LiveBench case |
| EfficiencyHigher is better · MM Efficiency v1.5 | UnrankedNot in the 38-model eligible cohort | #33 of 3846.0 score · 2/3 sources · provisional · missing ARC-AGI-2 · full-core range 43.3–59.9 |
| Pricing and Limits | ||
| Input priceFrom · USD / 1M tokens | $1.25Openai ↗ · Sep 3, 2026 | $1.25Xai ↗ · Sep 3, 2026 |
| Output priceFrom · USD / 1M tokens | $10.00Openai ↗ · Sep 3, 2026 | $2.50Xai ↗ · Sep 3, 2026 |
| Context windowMaximum documented tokens | 400K | 1,000K |
| Model facts checked | Sep 3, 2026View model evidence → | Sep 3, 2026View model evidence → |
Token prices are the lowest available sourced USD rates; input and output may use different providers. Cost ranking estimates output spend on LiveBench, not a full request bill. Ranking methodology →
Available Benchmarks
| Benchmark | GPT-5.1 | Grok 4.3 |
|---|---|---|
| LMArena Search Arenasearch-2026-08-24-d25aabda0010 · arena_rating · leader | 1,199.44100% of row best · rating · gpt-5.1-search; 95% CI [1194.20592738, 1204.68165473]; votes 59909; rank 14 | 1,164.8097% of row best · rating · grok-4.3; 95% CI [1159.64698972, 1169.95391272]; votes 91483; rank 23 |
| LMArena Text Arenatext-2026-09-13-d25aabda0010 · arena_rating · leader | 1,422.57100% of row best · rating · gpt-5.1; 95% CI [1418.95842118, 1426.18777801]; votes 42982; rank 100 | 1,397.7398% of row best · rating · grok-4.3; 95% CI [1394.01930088, 1401.44639527]; votes 66801; rank 145 |
| LMArena Vision Arenavision-2026-09-13-d25aabda0010 · arena_rating · statistical tie | 1,235.08100% of row best · rating · gpt-5.1; 95% CI [1227.35514387, 1242.80648733]; votes 10205; rank 65 | 1,229.47100% of row best · rating · grok-4.3; 95% CI [1223.17337452, 1235.75913440]; votes 22688; rank 67 |
| ToneBench2026-09-11-10-task-4ef099199c9c · overall_score · unverified | 75.98100% of row best · points · GPT-5.1 · 3,970 output tokens / case | 74.9199% of row best · points · Grok 4.3 (high) · 5,154 output tokens / case |
| Overall ResultCounted from the protocol-matched rows above · 1 tie | 2 benchmark winsNo overall winner | 0 benchmark winsNo overall winner |
Third-party benchmark Only like-for-like primary-publisher results are shown; raw scores, relative scores, configuration, and token spend remain visible.
Side-by-Side Facts
| Field | GPT-5.1 | Grok 4.3 |
|---|---|---|
| Developer | OpenAI | xAI |
| Family | Gpt 5 1 | Grok 4 |
| Model | GPT-5.1 | Grok 4.3 |
| Version | GPT-5.1 | Grok 4.3 |
| Lifecycle | active | active |
| Released | 2025-11-13 | 2026-06-17 |
| Knowledge cutoff | 2024-09-30 | Unknown |
| Input modalities | Text, Image | Text, Image |
| Output modalities | Text | Text |
| Context window | 400K | 1,000K |
| Total parameters | Unknown | Unknown |
| Active parameters | Unknown | Unknown |
| License | Unknown | Unknown |
| Open weights | No | No |
| API available | Yes | Yes |
| Self-hostable | No | No |
| Provider access | Openai (Standard), Openrouter (Standard) | Xai (Standard) |
| Capabilities | chat, generation, reasoning, structured_outputs, tools | chat, generation, reasoning, structured_outputs, tools |
GPT-5.1 Capabilities
Grok 4.3 Capabilities
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Primary Evidence
Sources and Freshness
Questions
GPT-5.1 vs Grok 4.3 FAQs
Is GPT-5.1 or Grok 4.3 better for coding?+
This comparison does not currently contain a protocol-matched coding benchmark for both GPT-5.1 and Grok 4.3, so Model Markets cannot name a coding leader from pricing, context size, or capability labels alone.
Which is cheaper, GPT-5.1 or Grok 4.3?+
GPT-5.1 is $1.25 and Grok 4.3 is $1.25 per million tokens, so they are tied on this metric. GPT-5.1 is $10.00 and Grok 4.3 is $2.50 per million tokens, so Grok 4.3 is cheaper on this metric.
Which has a larger context window, GPT-5.1 or Grok 4.3?+
Grok 4.3 has the larger sourced context window. GPT-5.1 supports 400K and Grok 4.3 supports 1,000K.
Which performs better in benchmarks, GPT-5.1 or Grok 4.3?+
There is no overall benchmark winner: An overall winner requires at least two decisive benchmarks from at least two original publishers.
Can GPT-5.1 or Grok 4.3 be self-hosted?+
Both models have the same recorded self-hosting status: unsupported. GPT-5.1 is not marked open weight; Grok 4.3 is not marked open weight.
Can GPT-5.1 and Grok 4.3 understand images?+
GPT-5.1 is documented with image input; Grok 4.3 is documented with image input. This reflects supported input modalities, not vision quality.
Which can generate longer answers, GPT-5.1 or Grok 4.3?+
Neither has a larger sourced maximum output. GPT-5.1 is 128K and Grok 4.3 is —.
Do GPT-5.1 and Grok 4.3 support reasoning and tool use?+
GPT-5.1: reasoning, tool calling, and image input. Grok 4.3: reasoning, tool calling, and image input. Feature support does not establish relative quality.
Which is available from more inference providers, GPT-5.1 or Grok 4.3?+
GPT-5.1 has 2 sourced provider routes; Grok 4.3 has 1, so GPT-5.1 has broader tracked availability.
Which offers better value, GPT-5.1 or Grok 4.3?+
There is no universal value winner. Compare the input and output prices above with the matched benchmark result for your workload: cheaper tokens can be offset by different quality, token usage, latency, or provider availability.