Gemini 3.5 Flash vs GPT-5.6 Terra
Benchmark Performance
Available Benchmarks
| Benchmark | Gemini 3.5 Flash | GPT-5.6 Terra |
|---|---|---|
| LMArena Agent Arenaagent-2026-08-31-011508720696 · outcome_score · leader | -4.0793% of row best · score · Gemini 3.5 Flash (Medium); 95% CI [-5.53391359, -2.59876989]; sessions 13762; observations 564442; rank 44 | 2.92100% of row best · score · GPT 5.6 Terra (xHigh); 95% CI [1.74076196, 4.09705014]; sessions 16778; observations 953717; rank 23 |
| LMArena Document Arenadocument-2026-07-30-011508720696 · arena_rating · statistical tie | 1,464.6599% of row best · rating · gemini-3.5-flash-medium; 95% CI [1454.40953837, 1474.88391002]; votes 3689; rank 17 | 1,479.21100% of row best · rating · gpt-5.6-terra-xhigh; 95% CI [1466.19331424, 1492.21945897]; votes 1969; rank 10 |
| LMArena Text Arenatext-2026-09-01-011508720696 · arena_rating · leader | 1,475.66100% of row best · rating · gemini-3.5-flash-medium; 95% CI [1471.01636052, 1480.30978904]; votes 32274; rank 17 | 1,446.7298% of row best · rating · gpt-5.6-terra-xhigh; 95% CI [1441.68248185, 1451.74987487]; votes 23942; rank 47 |
| LMArena Vision Arenavision-2026-08-27-011508720696 · arena_rating · leader | 1,306.20100% of row best · rating · gemini-3.5-flash-medium; 95% CI [1298.00721122, 1314.38427947]; votes 8261; rank 10 | 1,268.9997% of row best · rating · gpt-5.6-terra-xhigh; 95% CI [1259.82673197, 1278.15538857]; votes 5774; rank 33 |
| LiveBench2026-06-25 · overall · leader | 78.8496% of row best · percent · gemini-3.5-flash-high · 15,522 output tokens / case | 82.31100% of row best · percent · gpt-5.6-terra-max · 22,145 output tokens / case |
| ToneBench2026-08-14-10-task · overall_score · leader | 75.6087% of row best · points · Gemini 3.5 Flash (high thinking) · 13,604 output tokens / case | 86.60100% of row best · points · GPT-5.6 Terra (xhigh) · 4,819 output tokens / case |
| Overall ResultCounted from the protocol-matched rows above · 1 tie | 2 benchmark wins | 3 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 3.5 Flash | GPT-5.6 Terra |
|---|---|---|
| Developer | Google DeepMind | OpenAI |
| Family | Gemini 3 | Gpt 5 6 |
| Model | Gemini 3.5 Flash | GPT-5.6 Terra |
| Version | Gemini 3.5 Flash | GPT-5.6 Terra |
| Lifecycle | active | active |
| Released | Unknown | Unknown |
| Knowledge cutoff | Unknown | 2026-02-16 |
| Input modalities | Text, Image, Video, Audio, Document | Text, Image |
| Output modalities | Text | Text |
| 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) | OpenAI (Standard), Openrouter (Standard) |
| Capabilities | chat, generation, reasoning, tools | chat, generation, reasoning, tools |
13 comparable fields · 7 material differences · Pair passes the primary-source comparison gate
Gemini 3.5 Flash Capabilities
GPT-5.6 Terra Capabilities
Internal Comparison Graph
Related Comparisons
| A | Pair | B | Context |
|---|---|---|---|
Gemini 3 FlashGoogle DeepMind | vs | Gemini 3.5 FlashGoogle DeepMind | family variantstext |
Gemini 2.5 Flash-LiteGoogle DeepMind | vs | Gemini 3.5 FlashGoogle DeepMind | family variantstext |
Gemini 3.1 ProGoogle DeepMind | vs | Gemini 3.5 FlashGoogle DeepMind | family variantstext |
Gemini 2.5 FlashGoogle DeepMind | vs | Gemini 3.5 FlashGoogle DeepMind | family variantstext |
GPT-4.1OpenAI | vs | GPT-5.6 TerraOpenAI | family variantsimage, text |
GPT-4.1 MiniOpenAI | vs | GPT-5.6 TerraOpenAI | family variantsimage, text |
Claude Fable 5Anthropic | vs | GPT-5.6 TerraOpenAI | cross-developer peersimage, text |
Claude Mythos 5.1Anthropic | vs | GPT-5.6 TerraOpenAI | cross-developer peersimage, text |
Gemini 3.5 FlashGoogle DeepMind | vs |  GLM-5.3-FlashZ.ai | cross-developer peerstext |
Gemini 3.5 FlashGoogle DeepMind | vs |  Qwen3.8-FlashQwen | cross-developer peerstext |
Gemini Deep Research MaxGoogle DeepMind | vs | Gemini 3.5 FlashGoogle DeepMind | family variantstext |
Gemini 2.5 FlashGoogle DeepMind | vs | GPT-5.6 TerraOpenAI | cross-developer peerstext |
Primary Evidence
Sources and Freshness
Questions
Gemini 3.5 Flash vs GPT-5.6 Terra FAQs
Is Gemini 3.5 Flash or GPT-5.6 Terra better for coding?+
This comparison does not currently contain a protocol-matched coding benchmark for both Gemini 3.5 Flash and GPT-5.6 Terra, so Model Markets cannot name a coding leader from pricing, context size, or capability labels alone.
Which is cheaper, Gemini 3.5 Flash or GPT-5.6 Terra?+
Gemini 3.5 Flash is $1.50 and GPT-5.6 Terra is $2.00 per million tokens, so Gemini 3.5 Flash is cheaper on this metric. Gemini 3.5 Flash is $9.00 and GPT-5.6 Terra is $12.00 per million tokens, so Gemini 3.5 Flash is cheaper on this metric.
Which has a larger context window, Gemini 3.5 Flash or GPT-5.6 Terra?+
GPT-5.6 Terra has the larger sourced context window. Gemini 3.5 Flash supports 1,048,576 and GPT-5.6 Terra supports 1,050,000.
Which performs better in benchmarks, Gemini 3.5 Flash or GPT-5.6 Terra?+
GPT-5.6 Terra leads the current overall benchmark count. The result uses 6 protocol-matched benchmarks from 3 publishers; it is not a universal quality score.
Can Gemini 3.5 Flash or GPT-5.6 Terra be self-hosted?+
Both models have the same recorded self-hosting status: unsupported. Gemini 3.5 Flash is not marked open weight; GPT-5.6 Terra is not marked open weight.
Can Gemini 3.5 Flash and GPT-5.6 Terra understand images?+
Gemini 3.5 Flash is documented with image input; GPT-5.6 Terra is documented with image input. This reflects supported input modalities, not vision quality.
Which can generate longer answers, Gemini 3.5 Flash or GPT-5.6 Terra?+
GPT-5.6 Terra has the larger sourced maximum output: Gemini 3.5 Flash supports 65,536 and GPT-5.6 Terra supports 128,000 output tokens.
Do Gemini 3.5 Flash and GPT-5.6 Terra support reasoning and tool use?+
Gemini 3.5 Flash: reasoning, tool calling, and image input. GPT-5.6 Terra: reasoning, tool calling, and image input. Feature support does not establish relative quality.
Which is available from more inference providers, Gemini 3.5 Flash or GPT-5.6 Terra?+
Gemini 3.5 Flash has 1 sourced provider route; GPT-5.6 Terra has 2, so GPT-5.6 Terra has broader tracked availability.
Which offers better value, Gemini 3.5 Flash or GPT-5.6 Terra?+
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.