Best Factuality AI Models in 2026
As of October 5, 2026, the top model in best factuality ai models on the BenchLM leaderboard is Claude Opus 5.5 with a score of 64.4.
Bottom line: Factuality benchmarks are intentionally narrow — SimpleQA and HLE-no-tools are the primary signals. The category is still maturing, so treat the ranking as a shortlist.
This ranking moves when models ship. Get the releases, price changes and retirements that affect your shortlist. Follow model changes
Full Rankings (44 models)
Key Takeaways
The top model on this sourced reporting-family slice is Claude Opus 5.5 by Anthropic with an average of 64.4.
The best open-weight model is DeepSeek V4 Pro 0813 at position #4.
44 models are listed with sourced benchmark coverage in this reporting family.
Score in Context
What these scores mean
This is a reporting family ranking, not a weighted category. It averages sourced factuality benchmarks to give a focused view of this capability.
Known limitations
Models must have sourced results on at least a quarter of the benchmarks in this family to be included. Coverage varies — a model with 2 benchmark scores is less reliable than one with 5.
About this ranking
Ranking data as of October 5, 2026
This reporting page is intentionally narrow. It focuses on currently tracked sourced factuality signals such as SimpleQA, HLE without tools, and multimodal factuality. It is a reporting page, not a mature weighted category.
This page ranks models using only sourced factuality benchmarks in the reporting family.
Claude Opus 5.5 leads this ranking with a score of 64.4, followed by Claude Fable 5.1 (60.9) and Claude Mythos 5 (59). There is meaningful separation between the top models, suggesting genuine performance differences.
The best open-weight option is DeepSeek V4 Pro 0813 (ranked #4 with a score of 57.9). While proprietary models lead, open-weight options are within striking distance for teams willing to trade a few points of performance for full model control.
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.
Explore More
Know when it’s worth switching models
The model to choose, the cheaper alternative, and the release we would wait on.
Read a sample issueJoin 5,500+ readers.
One email each week. Unsubscribe anytime.