Gemini 3.1 Pro vs Grok 4.5
Benchmark Performance
Available Benchmarks
| Benchmark | Gemini 3.1 Pro | Grok 4.5 |
|---|---|---|
| LMArena Agent Arenaagent-2026-08-31-011508720696 · outcome_score · leader | -3.1391% of row best · score · Gemini 3.1 Pro Preview; 95% CI [-4.00806078, -2.24630473]; sessions 83248; observations 2709356; rank 40 | 6.06100% of row best · score · Grok 4.5; 95% CI [4.91016619, 7.21148996]; sessions 34008; observations 1655564; rank 13 |
| LMArena Document Arenadocument-2026-07-30-011508720696 · arena_rating · statistical tie | 1,445.3299% of row best · rating · gemini-3.1-pro-preview; 95% CI [1439.35538449, 1451.29339146]; votes 45162; rank 23 | 1,453.73100% of row best · rating · grok-4.5; 95% CI [1441.93744334, 1465.52785378]; votes 2435; rank 20 |
| LMArena Search Arenasearch-2026-08-24-011508720696 · arena_rating · statistical tie | 1,210.46100% of row best · rating · gemini-3.1-pro-grounding; 95% CI [1205.32063396, 1215.60669852]; votes 113282; rank 9 | 1,212.65100% of row best · rating · grok-4.5; 95% CI [1205.78347274, 1219.50889748]; votes 31505; rank 8 |
| LMArena Text Arenatext-2026-09-01-011508720696 · arena_rating · leader | 1,480.10100% of row best · rating · gemini-3.1-pro-preview; 95% CI [1476.89767236, 1483.30025658]; votes 102763; rank 11 | 1,451.8298% of row best · rating · grok-4.5; 95% CI [1446.90989155, 1456.73122428]; votes 25873; rank 39 |
| LMArena Vision Arenavision-2026-08-27-011508720696 · arena_rating · statistical tie | 1,295.39100% of row best · rating · gemini-3.1-pro-preview; 95% CI [1289.75236576, 1301.03738662]; votes 39412; rank 17 | 1,291.11100% of row best · rating · grok-4.5; 95% CI [1282.25469345, 1299.96666150]; votes 6401; rank 22 |
| LiveBench2026-06-25 · overall · leader | 81.66100% of row best · percent · gemini-3.1-pro-preview-high · 13,380 output tokens / case | 80.0198% of row best · percent · grok-4.5 · 10,517 output tokens / case |
| ToneBench2026-08-28-10-task-cd9819ab6e4d · overall_score · leader | 79.8997% of row best · points · Gemini 3.1 Pro (high thinking) · 10,009 output tokens / case | 82.23100% of row best · points · Grok 4.5 · 2,688 output tokens / case |
| Overall ResultCounted from the protocol-matched rows above · 3 ties | 2 benchmark winsTied overall | 2 benchmark winsTied overall |
Third-party benchmark Only like-for-like primary-publisher results are shown; raw scores, relative scores, configuration, and token spend remain visible.
Technical Differences
Side-by-Side Facts
| Field | Gemini 3.1 Pro | Grok 4.5 |
|---|---|---|
| Developer | Google DeepMind | xAI |
| Family | Gemini 3 | Grok 4 |
| Model | Gemini 3.1 Pro | Grok 4.5 |
| Version | Gemini 3.1 Pro | Grok 4.5 |
| Lifecycle | preview | active |
| Released | Unknown | 2026-07-16 |
| Knowledge cutoff | Unknown | Unknown |
| Input modalities | Text, Image, Video, Audio, Document | Text, Image |
| Output modalities | Text | Text |
| Context window | 1,049K | 500K |
| 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 | Google AI (Standard), Google Gemini (Standard) | Xai (Standard) |
| Capabilities | chat, generation, reasoning, tools | chat, generation, reasoning, structured_outputs, tools |
13 comparable fields · 9 material differences · Pair passes the primary-source comparison gate
Gemini 3.1 Pro Capabilities
Grok 4.5 Capabilities
Internal Comparison Graph
Related Comparisons
| A | Pair | B | Context |
|---|---|---|---|
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 DeepSeek-V4-ProDeepSeek | vs | Gemini 3.1 ProGoogle DeepMind | cross-developer peerstext |
Gemini 3.1 ProGoogle DeepMind | vs | Grok 4.6xAI | cross-developer peerstext |
Gemini 3.1 ProGoogle DeepMind | vs |  Qwen3.8-MaxQwen | cross-developer peerstext |
Gemini 3.1 ProGoogle DeepMind | vs |  Kimi-K3Moonshot AI | cross-developer peerstext |
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Gemini 3.1 ProGoogle DeepMind | vs |  GLM-5.3Z.ai | cross-developer peerstext |
Gemini 3.1 ProGoogle DeepMind | vs |  Hy4 previewTencent | cross-developer peerstext |
Seed 2.1 ProByteDance Seed | vs | Gemini 3.1 ProGoogle DeepMind | cross-developer peerstext |
Gemini 3.1 ProGoogle DeepMind | vs |  Mistral Large 3Mistral AI | cross-developer peerstext |
Primary Evidence
Sources and Freshness
Questions
Gemini 3.1 Pro vs Grok 4.5 FAQs
Is Gemini 3.1 Pro or Grok 4.5 better for coding?+
This comparison does not currently contain a protocol-matched coding benchmark for both Gemini 3.1 Pro and Grok 4.5, so Model Markets cannot name a coding leader from pricing, context size, or capability labels alone.
Which is cheaper, Gemini 3.1 Pro or Grok 4.5?+
Gemini 3.1 Pro is $2.00 and Grok 4.5 is $2.00 per million tokens, so they are tied on this metric. Gemini 3.1 Pro is $12.00 and Grok 4.5 is $6.00 per million tokens, so Grok 4.5 is cheaper on this metric.
Which has a larger context window, Gemini 3.1 Pro or Grok 4.5?+
Gemini 3.1 Pro has the larger sourced context window. Gemini 3.1 Pro supports 1,049K and Grok 4.5 supports 500K.
Which performs better in benchmarks, Gemini 3.1 Pro or Grok 4.5?+
There is no overall benchmark winner: The verified common benchmarks do not produce a majority winner.
Can Gemini 3.1 Pro or Grok 4.5 be self-hosted?+
Both models have the same recorded self-hosting status: unsupported. Gemini 3.1 Pro is not marked open weight; Grok 4.5 is not marked open weight.
Can Gemini 3.1 Pro and Grok 4.5 understand images?+
Gemini 3.1 Pro is documented with image input; Grok 4.5 is documented with image input. This reflects supported input modalities, not vision quality.
Which can generate longer answers, Gemini 3.1 Pro or Grok 4.5?+
Neither has a larger sourced maximum output. Gemini 3.1 Pro is 66K and Grok 4.5 is —.
Do Gemini 3.1 Pro and Grok 4.5 support reasoning and tool use?+
Gemini 3.1 Pro: reasoning, tool calling, and image input. Grok 4.5: reasoning, tool calling, and image input. Feature support does not establish relative quality.
Which is available from more inference providers, Gemini 3.1 Pro or Grok 4.5?+
Gemini 3.1 Pro has 2 sourced provider routes; Grok 4.5 has 1, so Gemini 3.1 Pro has broader tracked availability.
Which offers better value, Gemini 3.1 Pro or Grok 4.5?+
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.