Best AI Model for Long Documents (2026)
Ranked by Document Arena, where people upload PDFs and long files and vote on answers about them.
Best quality
Highest Document Arena score. Shown as a 0 to 100 relative score.
Highest Document Arena rating of the 9 models we price. $20.00 per 1M tokens blended.
Ranked 2 of 9, relative score 97. $10.00 per 1M tokens blended.
Ranked 3 of 9, relative score 96. $8.00 per 1M tokens blended.
Best value
Relative score divided by blended price. Only models at or above the median of the models we price qualify.
Relative score 83 for $4.50 per 1M tokens, 4x cheaper than Claude Fable 5.1.
Relative score 96 for $8.00 per 1M tokens, 2x cheaper than Claude Fable 5.1.
Relative score 97 for $10.00 per 1M tokens, 2x cheaper than Claude Fable 5.1.
About the 0 to 100 score: Relative score: 100 is the top model we price on Document Arena, 0 is the 50th ranked model on the full leaderboard. Raw scores differ by leaderboard, so we rescale them.
Leaderboard used: Document Arena.
Scores: LMArena Document Arena, leaderboard published Sep 13, 2026, via the LMArena leaderboard dataset (CC BY 4.0). Prices: our API prices table. Checked Oct 16, 2026.
How we pick
Quality is the LMArena score for each task, built from blind side by side human votes. Where a model is listed at several effort levels we use its best one. Value divides the score above the 50th ranked model on that leaderboard by the blended price, (3 x input + output) / 4 per 1M tokens, and only counts models at or above the median score of the models we price. Local picks use the same Text Arena score and the Q4 download size. Close scores are often inside the margin of error, so treat ranks 1 to 3 as a shortlist, not a final verdict.
Other good references: SWE-bench for fixing real code issues, Aider leaderboards for code editing, and each provider's model card.
FAQ
Which AI model is best for long PDFs?
Claude Fable 5.1 leads Document Arena among the models we price. GPT-5.6 Terra is the best value.
Does context window size matter?
Yes, but a bigger window does not mean better answers. Check both the score and the context size on our API prices table.
Other tasks
Coding · Chat · Creative writing · Roleplay and characters · Reasoning and math · Vision · Cheap bulk and agents · Local and private
Compare every price on API prices, or find what runs on your own hardware with the local model finder.