Gemini 3.1 Pro vs GPT-5.5
Benchmark Performance
Available Benchmarks
| Benchmark | Gemini 3.1 Pro | GPT-5.5 |
|---|---|---|
| LMArena Agent Arenaagent-2026-08-31-011508720696 · outcome_score · leader | -3.1392% of row best · score · Gemini 3.1 Pro Preview; 95% CI [-4.00806078, -2.24630473]; sessions 83248; observations 2709356; rank 40 | 4.84100% of row best · score · GPT 5.5; 95% CI [3.96340788, 5.71819765]; sessions 77762; observations 1908513; rank 18 |
| LMArena Document Arenadocument-2026-07-30-011508720696 · arena_rating · leader | 1,445.3298% of row best · rating · gemini-3.1-pro-preview; 95% CI [1439.35538449, 1451.29339146]; votes 45162; rank 23 | 1,480.30100% of row best · rating · gpt-5.5; 95% CI [1473.46488383, 1487.13183487]; votes 17286; rank 9 |
| LMArena Search Arenasearch-2026-08-24-011508720696 · arena_rating · leader | 1,210.4697% of row best · rating · gemini-3.1-pro-grounding; 95% CI [1205.32063396, 1215.60669852]; votes 113282; rank 9 | 1,242.05100% of row best · rating · gpt-5.5-search; 95% CI [1236.73488085, 1247.37053078]; votes 89873; rank 3 |
| 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 | 1,466.8099% of row best · rating · gpt-5.5; 95% CI [1462.99653821, 1470.60035247]; votes 64686; rank 27 |
| 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 | 1,294.36100% of row best · rating · gpt-5.5-high; 95% CI [1287.65516407, 1301.05910249]; votes 20121; rank 18 |
| LiveBench2026-06-25 · overall · leader | 81.6697% of row best · percent · gemini-3.1-pro-preview-high · 13,380 output tokens / case | 84.54100% of row best · percent · gpt-5.5-xhigh · 11,355 output tokens / case |
| ToneBench2026-08-28-10-task-cd9819ab6e4d · overall_score · leader | 79.8998% of row best · points · Gemini 3.1 Pro (high thinking) · 10,009 output tokens / case | 81.53100% of row best · points · GPT-5.5 (none) · 3,805 output tokens / case |
| Overall ResultCounted from the protocol-matched rows above · 1 tie | 1 benchmark win | 5 benchmark winsOverall lead |
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 | GPT-5.5 |
|---|---|---|
| Developer | Google Deepmind | Openai |
| Family | Gemini 3 | Gpt 5 5 |
| Model | Gemini 3.1 Pro | GPT-5.5 |
| Version | Gemini 3.1 Pro | GPT-5.5 |
| Lifecycle | preview | active |
| Released | Unknown | 2026-04-23 |
| Knowledge cutoff | Unknown | 2025-12-01 |
| Input modalities | Unknown | Unknown |
| Output modalities | Unknown | Unknown |
| Context window | 1,048,576 | 1,050,000 |
| 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) | Openai (Standard), Openrouter (Standard) |
| Capabilities | chat, generation, reasoning, tools | chat, generation, reasoning, structured_outputs, tools |
11 comparable fields · 8 material differences · Interactive comparison only; indexing gate not met
Gemini 3.1 Pro Capabilities
GPT-5.5 Capabilities
Internal Comparison Graph
Related Comparisons
| A | Pair | B | Context |
|---|---|---|---|
Claude Fable 5.1Anthropic | vs | Gemini 3.1 ProGoogle DeepMind | cross-developer peerstext |
Claude Mythos 5.1Anthropic | vs | Gemini 3.1 ProGoogle DeepMind | cross-developer peerstext |
 DeepSeek-V4-Flash-Vision-ExpDeepSeek | vs | Gemini 3.1 ProGoogle DeepMind | cross-developer peerstext |
Gemini 3.1 ProGoogle DeepMind | vs |  Hy4 previewTencent | cross-developer peerstext |
Gemini 3.1 ProGoogle DeepMind | vs | Gemini 3.8 FlashGoogle DeepMind | family variantstext |
GPT-5.4OpenAI | vs | GPT-5.5OpenAI | family variantsimage, text |
Gemini 2.5 ProGoogle DeepMind | vs | Gemini 3.1 ProGoogle DeepMind | family variantstext |
GPT-5.4 ProOpenAI | vs | GPT-5.5OpenAI | family variantsimage, text |
GPT-5.1OpenAI | vs | GPT-5.5OpenAI | family variantsimage, text |
Gemini 3.1 ProGoogle DeepMind | vs | Gemini 3.5 FlashGoogle DeepMind | family variantstext |
Claude Opus 4.6Anthropic | vs | GPT-5.5OpenAI | cross-developer peersimage, text |
Claude Opus 4.7Anthropic | vs | GPT-5.5OpenAI | cross-developer peersimage, text |
Primary Evidence
Sources and Freshness
Questions
Gemini 3.1 Pro vs GPT-5.5 FAQs
Is Gemini 3.1 Pro or GPT-5.5 better for coding?+
This comparison does not currently contain a protocol-matched coding benchmark for both Gemini 3.1 Pro and GPT-5.5, so Model Markets cannot name a coding leader from pricing, context size, or capability labels alone.
Which is cheaper, Gemini 3.1 Pro or GPT-5.5?+
Gemini 3.1 Pro is $2.00 and GPT-5.5 is $5.00 per million tokens, so Gemini 3.1 Pro is cheaper on this metric. Gemini 3.1 Pro is $12.00 and GPT-5.5 is $30.00 per million tokens, so Gemini 3.1 Pro is cheaper on this metric.
Which has a larger context window, Gemini 3.1 Pro or GPT-5.5?+
GPT-5.5 has the larger sourced context window. Gemini 3.1 Pro supports 1,048,576 and GPT-5.5 supports 1,050,000.
Which performs better in benchmarks, Gemini 3.1 Pro or GPT-5.5?+
GPT-5.5 leads the current overall benchmark count. The result uses 7 protocol-matched benchmarks from 3 publishers; it is not a universal quality score.
Can Gemini 3.1 Pro or GPT-5.5 be self-hosted?+
Both models have the same recorded self-hosting status: unsupported. Gemini 3.1 Pro is not marked open weight; GPT-5.5 is not marked open weight.
Can Gemini 3.1 Pro and GPT-5.5 understand images?+
Gemini 3.1 Pro is not documented with image input; GPT-5.5 is not documented with image input. This reflects supported input modalities, not vision quality.
Which can generate longer answers, Gemini 3.1 Pro or GPT-5.5?+
GPT-5.5 has the larger sourced maximum output: Gemini 3.1 Pro supports 65,536 and GPT-5.5 supports 128,000 output tokens.
Do Gemini 3.1 Pro and GPT-5.5 support reasoning and tool use?+
Gemini 3.1 Pro: reasoning and tool calling. GPT-5.5: reasoning and tool calling. Feature support does not establish relative quality.
Which is available from more inference providers, Gemini 3.1 Pro or GPT-5.5?+
Gemini 3.1 Pro has 2 sourced provider routes; GPT-5.5 has 2, a tie.
Which offers better value, Gemini 3.1 Pro or GPT-5.5?+
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.