Models with the longest context window
Which model handles the longest documents?
As of 18 September 2026, the model ranking first for this question is SpaceXAI: Grok 4.20 on OpenRouter, with context window 2 000 000 and an output price of $2.50 per million tokens. Ranked by largest published context window, then lowest input price, across 502 models for which we hold both figures. This ranking ignores speed and reliability: it is a query on price and a relayed capability score, not a verdict on which model serves you best.
How this ranking is built
Criterion: largest published context window, then lowest input price. Context length is published by the provider, not measured by us. A long window says what the model accepts, not how well it uses it.
This is a query, not an opinion. Both figures are shown on every row so you can check the order, and the table sorts on any column if you disagree with our criterion.
Two things to know before trusting this table. Capability scores are published by Artificial Analysis and relayed by the catalogue we read. They are not our measurement, and a score measures the model rather than the seller, so we apply it to every seller of that model. This ranking says nothing about speed or reliability, which we measure only in part: availability is published per upstream host in reliability.json and on the model pages, and we publish no latency at all, for reasons given on the data page. Prices are ours to observe, each carries the date we saw it, and we keep only the cheapest offer per model so that batch and free tiers do not crowd out the answer.
| # | Model | Seller | Context windowtokens40 of 40 heldScale from 512 to 2M | Input$ / 1M tokens38 of 40 heldScale from $0.0001 to $600 | Output$ / 1M tokens38 of 40 heldScale from $0.0001 to $600 | Contexttokens40 of 40 heldScale from 512 to 2M | Observed |
|---|---|---|---|---|---|---|---|
| 1 | SpaceXAI: Grok 4.20 | OpenRouter | 2 000 000 | $1.25 | $2.50 | 2 000 000 | 18 September 2026 |
| 2 | SpaceXAI: Grok 4.20 Multi-Agent | OpenRouter | 2 000 000 | $1.25 | $2.50 | 2 000 000 | 18 September 2026 |
| 3 | Auto Router | OpenRouter | 2 000 000 | n/a | n/a | 2 000 000 | 18 September 2026 |
| 4 | Pareto Code Router | OpenRouter | 2 000 000 | n/a | n/a | 2 000 000 | 18 September 2026 |
| 5 | DeepSeek: DeepSeek V4 Flash Latest | OpenRouter | 1 310 720 | $0.055 | $0.165 | 1 310 720 | 18 September 2026 |
| 6 | DeepSeek: DeepSeek V4 Flash 0731 | OpenRouter | 1 310 720 | $0.060 | $0.120 | 1 310 720 | 18 September 2026 |
| 7 | Z.ai: GLM Flash Latest | OpenRouter | 1 310 720 | $0.075 | $0.250 | 1 310 720 | 17 September 2026 |
| 8 | Z.ai: GLM 5.3 Flash | OpenRouter | 1 310 720 | $0.090 | $0.300 | 1 310 720 | 18 September 2026 |
| 9 | Meta: Llama 4 Scout | OpenRouter | 1 310 720 | $0.100 | $0.300 | 1 310 720 | 18 September 2026 |
| 10 | Z.ai: GLM Latest | OpenRouter | 1 310 720 | $0.900 | $3.00 | 1 310 720 | 18 September 2026 |
| 11 | OpenAI: GPT-5.6 Luna | OpenRouter | 1 050 000 | $0.200 | $1.20 | 1 050 000 | 18 September 2026 |
| 12 | OpenAI: GPT-5.6 Luna Pro | OpenRouter | 1 050 000 | $0.200 | $1.20 | 1 050 000 | 18 September 2026 |
| 13 | OpenAI: GPT Luna Latest | OpenRouter | 1 050 000 | $0.200 | $1.20 | 1 050 000 | 18 September 2026 |
| 14 | Xiaomi: MiMo-V2.5-Pro | OpenRouter | 1 050 000 | $0.435 | $0.870 | 1 050 000 | 18 September 2026 |
| 15 | OpenAI: GPT-5.6 Sol | OpenRouter | 1 050 000 | $2.00 | $10.00 | 1 050 000 | 18 September 2026 |
| 16 | OpenAI: GPT-5.6 Sol Pro | OpenRouter | 1 050 000 | $2.00 | $10.00 | 1 050 000 | 18 September 2026 |
| 17 | OpenAI: GPT-5.6 Terra | OpenRouter | 1 050 000 | $2.00 | $12.00 | 1 050 000 | 18 September 2026 |
| 18 | OpenAI: GPT-5.6 Terra Pro | OpenRouter | 1 050 000 | $2.00 | $12.00 | 1 050 000 | 18 September 2026 |
| 19 | OpenAI GPT Latest | OpenRouter | 1 050 000 | $2.00 | $10.00 | 1 050 000 | 10 September 2026 |
| 20 | OpenAI: GPT Sol Latest | OpenRouter | 1 050 000 | $2.00 | $10.00 | 1 050 000 | 18 September 2026 |
| 21 | OpenAI: GPT Terra Latest | OpenRouter | 1 050 000 | $2.00 | $12.00 | 1 050 000 | 18 September 2026 |
| 22 | OpenAI: GPT-5.4 | OpenRouter | 1 050 000 | $2.50 | $15.00 | 1 050 000 | 18 September 2026 |
| 23 | OpenAI: GPT-5.5 | OpenRouter | 1 050 000 | $5.00 | $30.00 | 1 050 000 | 18 September 2026 |
| 24 | OpenAI: GPT-6 Astra | OpenRouter | 1 050 000 | $10.00 | $50.00 | 1 050 000 | 18 September 2026 |
| 25 | OpenAI: GPT-6 Astra Pro | OpenRouter | 1 050 000 | $10.00 | $50.00 | 1 050 000 | 18 September 2026 |
| 26 | OpenAI: GPT Astra Latest | OpenRouter | 1 050 000 | $10.00 | $50.00 | 1 050 000 | 18 September 2026 |
| 27 | OpenAI: GPT-5.4 Pro | OpenRouter | 1 050 000 | $30.00 | $180 | 1 050 000 | 18 September 2026 |
| 28 | OpenAI: GPT-5.5 Pro | OpenRouter | 1 050 000 | $30.00 | $180 | 1 050 000 | 18 September 2026 |
| 29 | Meituan: LongCat 2.0 | OpenRouter | 1 048 756 | $0.300 | $1.20 | 1 048 756 | 18 September 2026 |
| 30 | Google: Lyria 3 Clip Preview | OpenRouter | 1 048 576 | $0.000 | $0.000 | 1 048 576 | 18 September 2026 |
| 31 | Google: Lyria 3 Pro Preview | OpenRouter | 1 048 576 | $0.000 | $0.000 | 1 048 576 | 18 September 2026 |
| 32 | Ox Alpha | OpenRouter | 1 048 576 | $0.000 | $0.000 | 1 048 576 | 25 August 2026 |
| 33 | DeepSeek: DeepSeek V4 Flash 0423 | OpenRouter | 1 048 576 | $0.04984 | $0.09968 | 1 048 576 | 18 September 2026 |
| 34 | Poolside: Laguna S 2.1 | OpenRouter | 1 048 576 | $0.090 | $0.180 | 1 048 576 | 18 September 2026 |
| 35 | Google: Gemini 2.5 Flash Lite | OpenRouter | 1 048 576 | $0.100 | $0.400 | 1 048 576 | 18 September 2026 |
| 36 | Meta: Muse Spark 1.2 Contributor | OpenRouter | 1 048 576 | $0.100 | $0.200 | 1 048 576 | 18 September 2026 |
| 37 | Meta: Muse Spark 1.3 Contributor | OpenRouter | 1 048 576 | $0.100 | $0.200 | 1 048 576 | 18 September 2026 |
| 38 | DeepSeek: DeepSeek Flash Latest | OpenRouter | 1 048 576 | $0.150 | $0.600 | 1 048 576 | 18 September 2026 |
| 39 | Meta: Llama 4 Maverick | OpenRouter | 1 048 576 | $0.1875 | $0.6525 | 1 048 576 | 18 September 2026 |
| 40 | deepseek-ai/DeepSeek-V4.1-Flash | DeepInfra | 1 048 576 | $0.200 | $0.600 | 1 048 576 | 18 September 2026 |
502 models meet this criterion. The table shows the first 40, so 462 ranked below the cut are not listed here; the full catalogue holds them all.
A model missing from this table is missing one of the two figures, not judged. We would rather show a shorter list than fill it with guesses.