October 2026
Best AI model for long documents
Ranked by context window, the amount of text a model reads in one request, with its overall LMArena rating alongside so a big window is not mistaken for a good model.
| # | Model | Context | Overall rating | Input / 1M | Output / 1M |
|---|---|---|---|---|---|
| 1 | GPT 5.5OpenAI | 1.1M | 1471 | $5.00 | $30.00 |
| 2 | GPT 5.5OpenAI | 1.1M | 1471 | $5.00 | $30.00 |
| 3 | GPT 5.4OpenAI | 1.1M | 1469 | $2.50 | $15.00 |
| 4 | GPT 5.4OpenAI | 1.1M | 1469 | $2.50 | $15.00 |
| 5 | GPT 5.6 SolOpenAI | 1.1M | 1457 | $4.00 | $20.00 |
| 6 | GPT 6.1 SolOpenAI | 1.1M | 1448 | $2.00 | $10.00 |
| 7 | GPT 5.6 TerraOpenAI | 1.1M | 1447 | $2.00 | $12.00 |
| 8 | GPT 6 AstraOpenAI | 1.1M | 1443 | $10.00 | $50.00 |
| 9 | GPT 5.6 LunaOpenAI | 1.1M | 1431 | $0.200 | $1.20 |
| 10 | GPT 6 SolOpenAI | 1.1M | 1398 | $2.00 | $10.00 |
| 11 | GPT 6 LunaOpenAI | 1.1M | 1392 | $0.100 | $0.500 |
| 12 | Gemini 4 ArgonGoogle | 1M | 1532 | $2.00 | $10.00 |
Ratings from LMArena, snapshot 2026-10-13, used under its licence with attribution. Prices are what Rapid Router bills per request.
Compare the leaders
How this is ranked
Context window is the published maximum input for each model on the gateway. The overall LMArena rating sits beside it so a long window is weighed against quality.
Only models that are live and paid on Rapid Router are listed; free-tier and preview models are on the catalog. For your own monthly cost on any of them, use the cost calculator.
Common questions
What is the best ai model for long documents?
GPT 5.5 by OpenAI ranks first by context window (1.1M) as of October 2026.
How do I use these models?
Every model here is callable at https://rapidrouter.ai/api/v1 with one Rapid Router key and the OpenAI SDK; switching between them is a one-string change. Each model's page has a ready request.
How often does this ranking change?
It is read from the latest LMArena snapshot (2026-10-13) and the live catalog every time the page loads, so new models and new votes show up without anyone editing the page.
Other rankings: coding · building web apps · hard, multi-step problems · math · writing · following detailed instructions · understanding images · general chat · a tight budget