Best Large Context Window LLMs in 2026
As of October 19, 2026, the top model among large context window LLMs on the BenchLM leaderboard is Claude Opus 5.5 with a score of 86.7.
Bottom line: A large context window means nothing if the model can't actually use it. Most of the top overall rows now list windows of 1M tokens or more, so check the long-context benchmarks, not the window size, before choosing.
Full Rankings (159 ranked, 1 tracked)
Public preview through Mistral Studio; Mistral says the weights are due by the end of October 2026.
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tracked
Key Takeaways
The top model is Claude Opus 5.5 by Anthropic with a BenchAlign v5.8 score of 86.7 and Supported evidence.
The best open-weight model is MiMo-V2.6-Pro at position #11.
159 models are ranked here; 1 tracked model is listed without a position.
Score in Context
What these scores mean
Models are filtered by context window (200K+ tokens) and ranked by overall BenchLM score. A large context window alone is not enough — check long-context benchmark scores for actual retrieval and reasoning quality.
Known limitations
Context window size is self-reported by providers. Actual usable context may be smaller due to edge degradation. Long-context benchmarks test specific patterns — real workloads may differ.
About this ranking
Ranking data as of October 19, 2026
AI models with the largest context windows (200K+ tokens), ranked by benchmark performance.
Unless noted otherwise, ranking surfaces on this page use BenchLM’s provisional leaderboard lane rather than the stricter sourced-only verified leaderboard.
Claude Opus 5.5 leads this ranking with a score of 86.7, followed by GPT-6.1 Sol (84.2) and GPT-6 Astra (84.1). The top three are separated by just a few points — any of them would perform well for this use case.
The best open-weight option is MiMo-V2.6-Pro (ranked #11 with a score of 73.7). Proprietary models hold a clear advantage in this category, though open-weight options may suffice for less demanding use cases.
This ranking uses provisional overall weighted scores from the active scoring formula. For detailed model profiles, click any model name above. To compare two specific models head-to-head, use the "vs #" links.
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