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Best Factuality AI Models in 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.

Bottom line: Factuality benchmarks are intentionally narrow — SimpleQA and HLE-no-tools are the primary signals. Claude Mythos Preview leads, but this category is still maturing.

According to BenchLM.ai, Claude Mythos Preview leads this ranking with a score of 56.8, followed by Claude Opus 4.7 (46.9) and Gemini 3.1 Pro (45.4). There is a significant gap between the leading models and the rest of the field.

The best open-weight option is Gemma 4 31B (ranked #11 with a score of 19.5). Proprietary models hold a clear advantage in this category, though open-weight options may suffice for less demanding use cases.

This ranking is based on provisional overall weighted scores across BenchLM.ai's scoring formula tracked by BenchLM.ai. For detailed model profiles, click any model name below. To compare two specific models head-to-head, use the "vs #" links.

What changed

Claude Mythos Preview leads factuality with the best SimpleQA and HLE-no-tools scores.

Gemini 3.1 Pro strong factuality for a non-reasoning model.

GPT-5.4 solid SimpleQA performance, especially on knowledge-heavy queries.

How to choose

Full Rankings (12 models)

Claude Mythos Preview
Anthropic·Proprietary·1M

56.8

sourced avg

Claude Opus 4.7
Anthropic·Proprietary·1M

46.9

sourced avg

Gemini 3.1 Pro
Google·Proprietary·1M

45.4

sourced avg

4
Muse Spark
Meta·Proprietary·262K

42.8

sourced avg

5
GPT-5.4 Pro
OpenAI·Proprietary·1.05M

42.7

sourced avg

6
Claude Opus 4.6
Anthropic·Proprietary·1M

40

sourced avg

7
GPT-5.4
OpenAI·Proprietary·1.05M

39.8

sourced avg

8
Grok 4.20
xAI·Proprietary·2M

31.6

sourced avg

9
GPT-5.4 mini
OpenAI·Proprietary·400K

28.2

sourced avg

10
GPT-5.4 nano
OpenAI·Proprietary·400K

24.3

sourced avg

11
Gemma 4 31B
Google·Open Weight·256K

19.5

sourced avg

12
Gemma 4 26B A4B
Google·Open Weight·256K

8.7

sourced avg

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Key Takeaways

The top model on this sourced reporting-family slice is Claude Mythos Preview by Anthropic with an average of 56.8.

The best open-weight model is Gemma 4 31B at position #11.

12 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.

Last updated: April 16, 2026

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