AI models with the longest context window
The context window is how much text a model can read in one request: instructions, documents and conversation included. One million tokens is roughly 1,900 pages of text.
Our picks
The ranking
Compare the top two| # | Model | Contexti | Overall indexi | Inputi | Outputi | Contexti |
|---|---|---|---|---|---|---|
| 1 | Grok 4.20xAI | 2M | 152.0 | $1.25 | $2.50 | 2M |
| 2 | 2M | — | $1.25 | $2.50 | 2M | |
| 3 | Llama 4 ScoutMeta | 1.3M | 129.6 | $0.10 | $0.30 | 1.3M |
| 4 | GPT-6 AstraOpenAI | 1.1M | 166.6 | $10 | $50 | 1.1M |
| 5 | GPT-5.5 ProOpenAI | 1.1M | 162.5 | $30 | $180 | 1.1M |
| 6 | GPT-5.6 SolOpenAI | 1.1M | 162.0 | $2 | $10 | 1.1M |
| 7 | GPT-5.6 TerraOpenAI | 1.1M | 159.3 | $2 | $12 | 1.1M |
| 8 | GPT-5.5OpenAI | 1.1M | 159.3 | $5 | $30 | 1.1M |
| 9 | GPT-5.4 ProOpenAI | 1.1M | 159.1 | $30 | $180 | 1.1M |
| 10 | GPT-5.4OpenAI | 1.1M | 156.9 | $2.50 | $15 | 1.1M |
per 1M tokens · USD
Quick answers
- Which AI model has the largest context window?
- Grok 4.20 from xAI leads this ranking (Context: 2M). It costs $1.25 per million input tokens and $2.50 per million output tokens.
How we rank
Scores come from tests run independently by Epoch AI (CC BY 4.0), not from the companies’ own announcements. Prices come from OpenRouter’s public API. Both are refreshed automatically several times a day, so this ranking follows new releases and price changes.
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