LLM Context Window Comparison
Updated Free mock REST & WebSocket APIs
See how much text each model can take in one request. The chart compares context windows (or max output) across OpenAI, Anthropic, Google, Mistral, Meta, DeepSeek and xAI, and the fit check shows which models can hold your prompt.
- GPT-5.6 SolOpenAI1.05M922K max in
- GPT-5.6 TerraOpenAI1.05M922K max in
- GPT-6 AstraOpenAI1.05M
- GPT-6 LunaOpenAI1.05M
- GPT-6 SolOpenAI1.05M922K max in
- GPT-6.1 SolOpenAI1.05M
- Gemini 2.5 ProGoogle1M
- Gemini 3.1 Flash-LiteGoogle1M
- Gemini 3.1 Pro (preview)Google1M
- Gemini 3.5 Flash-LiteGoogle1M
- Gemini 3.8 FlashGoogle1M
- Gemini 4 ArgonGoogle1M
- Claude Fable 5.1Anthropic1M
- Claude Opus 4.8Anthropic1M
- Claude Opus 5Anthropic1M
- Claude Opus 5.5Anthropic1M
- Claude Sonnet 5Anthropic1M
- Claude Sonnet 5.5Anthropic1M
- DeepSeek FlashDeepSeek1M
- DeepSeek V4 ProDeepSeek1M
- Grok 4.3xAI1M
- Mistral Large 4Mistral1M
- Grok 4.7xAI500K
- Grok Build 0.1xAI256K
- Ministral 3 8BMistral256K
- Mistral Medium 3.5Mistral256K
- Mistral Small 4Mistral256K
- Llama 3.3 70BMeta (Llama) · Together AI128K
- CodestralMistral128K
Prices checked on 2026-10-18 from each provider's official pricing page (standard tier, USD per 1M tokens). Prices change often — verify before you budget.
How to compare context windows
- Pick providers, and switch between context window and maximum output tokens.
- Type your prompt size (e.g. 150k) to see which models can hold it — models that can't turn red.
- Check the full table below for exact limits, including separate maximum-input caps.
What a context window is
The context window is the maximum number of tokens a model can consider in one request: your system prompt, the conversation history, any documents or tool results, and the response it generates. If input plus output exceeds it, the request fails or old messages must be dropped. Some models also cap input separately — GPT-5 has a 400K window but accepts at most 272K input tokens.
All context windows
| Model | Context window | Max output | ≈ English words |
|---|---|---|---|
| GPT-5.4 (OpenAI) | 1,050,000 | 128,000 | 788K |
| GPT-5.5 (OpenAI) | 1,050,000 | 128,000 | 788K |
| GPT-5.6 Luna (OpenAI) | 1,050,000 max input 922,000 | 128,000 | 788K |
| GPT-5.6 Sol (OpenAI) | 1,050,000 max input 922,000 | 128,000 | 788K |
| GPT-5.6 Terra (OpenAI) | 1,050,000 max input 922,000 | 128,000 | 788K |
| GPT-6 Astra (OpenAI) | 1,050,000 | 128,000 | 788K |
| GPT-6 Luna (OpenAI) | 1,050,000 | 128,000 | 788K |
| GPT-6 Sol (OpenAI) | 1,050,000 max input 922,000 | 128,000 | 788K |
| GPT-6.1 Sol (OpenAI) | 1,050,000 | 128,000 | 788K |
| Gemini 2.5 Flash (Google) | 1,048,576 | 65,536 | 786K |
| Gemini 2.5 Flash-Lite (Google) | 1,048,576 | 65,536 | 786K |
| Gemini 2.5 Pro (Google) | 1,048,576 | 65,536 | 786K |
| Gemini 3.1 Flash-Lite (Google) | 1,048,576 | 65,536 | 786K |
| Gemini 3.1 Pro (preview) (Google) | 1,048,576 | 65,536 | 786K |
| Gemini 3.5 Flash-Lite (Google) | 1,048,576 | 65,536 | 786K |
| Gemini 3.8 Flash (Google) | 1,048,576 | 65,536 | 786K |
| Gemini 4 Argon (Google) | 1,048,576 | 65,536 | 786K |
| GPT-4.1 (OpenAI) | 1,047,576 | 32,768 | 786K |
| GPT-4.1 mini (OpenAI) | 1,047,576 | 32,768 | 786K |
| Claude Fable 5.1 (Anthropic) | 1,000,000 | 128,000 | 750K |
| Claude Haiku 5.5 (Anthropic) | 1,000,000 | 128,000 | 750K |
| Claude Opus 4.8 (Anthropic) | 1,000,000 | 128,000 | 750K |
| Claude Opus 5 (Anthropic) | 1,000,000 | 128,000 | 750K |
| Claude Opus 5.5 (Anthropic) | 1,000,000 | 128,000 | 750K |
| Claude Sonnet 4.6 (Anthropic) | 1,000,000 | 128,000 | 750K |
| Claude Sonnet 5 (Anthropic) | 1,000,000 | 128,000 | 750K |
| Claude Sonnet 5.5 (Anthropic) | 1,000,000 | 128,000 | 750K |
| DeepSeek Flash (DeepSeek) | 1,000,000 | 384,000 | 750K |
| DeepSeek V4 Pro (DeepSeek) | 1,000,000 | 384,000 | 750K |
| Grok 4.3 (xAI) | 1,000,000 | — | 750K |
| Mistral Large 4 (Mistral) | 1,000,000 | — | 750K |
| Grok 4.7 (xAI) | 500,000 | — | 375K |
| GPT-5 (OpenAI) | 400,000 max input 272,000 | 128,000 | 300K |
| GPT-5 mini (OpenAI) | 400,000 max input 272,000 | 128,000 | 300K |
| GPT-5 nano (OpenAI) | 400,000 max input 272,000 | 128,000 | 300K |
| GPT-5.4 mini (OpenAI) | 400,000 max input 272,000 | 128,000 | 300K |
| GPT-5.4 nano (OpenAI) | 400,000 max input 272,000 | 128,000 | 300K |
| Grok Build 0.1 (xAI) | 256,000 | — | 192K |
| Ministral 3 8B (Mistral) | 256,000 | — | 192K |
| Mistral Medium 3.5 (Mistral) | 256,000 | — | 192K |
| Mistral Small 4 (Mistral) | 256,000 | — | 192K |
| Claude Haiku 4.5 (Anthropic) | 200,000 | 64,000 | 150K |
| o3 (OpenAI) | 200,000 | 100,000 | 150K |
| o4-mini (OpenAI) | 200,000 | 100,000 | 150K |
| gpt-oss-120b (OpenAI · Groq) | 131,072 | 65,536 | 98K |
| gpt-oss-20b (OpenAI · Groq) | 131,072 | 65,536 | 98K |
| Llama 3.3 70B (Meta (Llama) · Together AI) | 131,072 | — | 98K |
| Codestral (Mistral) | 128,000 | — | 96K |
| GPT-4o (OpenAI) | 128,000 | 16,384 | 96K |
| GPT-4o mini (OpenAI) | 128,000 | 16,384 | 96K |
Bigger isn't automatically better
- Cost scales with what you send. A full 1M-token prompt on GPT-6 Sol costs $4.00 per call — and long-context surcharges kick in above 272K on OpenAI and 200K on Gemini Pro and Grok.
- Recall drops in the middle. Models retrieve facts near the start and end of long prompts more reliably; put key instructions last.
- Latency grows with prompt length. Retrieval (RAG) that sends only relevant chunks is often faster and cheaper than stuffing everything in.
Context sizes in tokens: 1M tokens ≈ 750,000 English words ≈ 1,500 pages. Count your own text with the token counter.
Related tools
Frequently asked questions
Which LLM has the largest context window?
Several current models accept about 1M tokens: GPT-6 and GPT-5.4+ (1.05M), Claude Fable, Opus, Sonnet and Haiku 5.5 (1M), Gemini (1,048,576), Mistral Large 4, Grok 4.3 and DeepSeek V4 (1M).
Do output tokens count toward the context window?
Yes. Input and output share the window, so a 128K model given 120K tokens of input can only reply with about 8K tokens.
How many pages fit in 200K tokens?
About 150,000 English words, or roughly 300 pages at 500 words per page. Code and non-English text fit less.
Are these limits up to date?
Limits were checked on 2026-10-18 from each provider's model documentation. Providers raise limits often, so verify for your account and API tier.
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