Best AI model for research and long documents
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The verdict
- Scores 96 on overall, #2 of 31 models we track for this job.
- $55.00 per 1,000 reports.
- Reads up to 1,049K tokens at once.
- Scores 71 on overall, #9 of 31 models we track for this job.
- $20.63 per 1,000 reports, 63% less than the best overall pick.
- The cheapest model that passes our test for research and long documents.
- Scores 97 on overall, the highest of 31 models we track for this job.
- $110 per 1,000 reports: the extra $55.00 per 1,000 buys 1 more points.
- Reads up to 1,000K tokens at once.
Long documents need two things: a context window big enough to read everything at once, and the judgement to pull out what matters. We only consider models that read at least 200,000 tokens in one go.
How we tested
Quality is the overall score, half Arena votes and half Epoch AI’s index of hard benchmarks. A report is about 20,000 tokens in and 1,500 out.
Scores are provisional until our own test rig runs these tasks. A model “passes our test” for this job at a score of 60 or more.
Scores and cost at your volume
| Model | Score | Passes | 1k reports a month | 10k reports a month | 100k reports a month |
|---|---|---|---|---|---|
| Claude Opus 5.5 | 97 | Yes | $110 | $1100 | $11000 |
| Gemini 4 Argon | 96 | Yes | $55.00 | $550 | $5500 |
| Claude Fable 5.1 | 92 | Yes | $275 | $2750 | $27500 |
| Claude Opus 5 | 86 | Yes | $138 | $1375 | $13750 |
| Muse Wonder | 80 | Yes | $110 | $1100 | $11000 |
| Claude Sonnet 5.5 | 79 | Yes | $55.00 | $550 | $5500 |
| GPT-6 Astra | 74 | Yes | $275 | $2750 | $27500 |
| GPT-6.1 Sol | 74 | Yes | $55.00 | $550 | $5500 |
| Gemini 3.8 Flash | 71 | Yes | $20.63 | $206 | $2063 |
| Muse Spark 1.3 | 68 | Yes | $31.38 | $314 | $3138 |
| GPT-5.6 Sol | 68 | Yes | $110 | $1100 | $11000 |
| Qwen3.8 Max | 66 | Yes | $49.00 | $490 | $4900 |
One report is about 20,000 tokens in and 1,500 out, at list prices. Try your own numbers in the cost calculator.
Who should pick something else
- For contracts you will sign, treat any model’s summary as a first read, not advice.
- If you only need short summaries, the summaries guide is far cheaper.
Questions
Which AI can read the longest documents?
The model pages list each model’s context window. Every model in this guide reads at least 200,000 tokens, roughly 500 pages.
Is the most expensive model worth it for research?
When accuracy across a long document matters, often yes. The premium pick shows what the extra cost buys.
Changes to this guide
- 25 Oct 2026: First version, on provisional scores from Arena and Epoch AI.