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BenchLM recommendation

Best Factuality AI Models in 2026

Data verified

As of July 23, 2026, the top model in best factuality ai models on the BenchLM leaderboard is Claude Mythos 5 with a score of 59.

Last verified: July 23, 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 Fable 5 leads, but this category is still maturing.

Claude Mythos 5 leads this ranking with a score of 59, followed by DeepSeek V4 Pro (Max) (57.9) and DeepSeek V4 Pro Base (55.2). There is meaningful separation between the top models, suggesting genuine performance differences.

The best open-weight option is DeepSeek V4 Pro (Max) (ranked #2 with a score of 57.9). Open-weight models are highly competitive in this category — self-hosting is a viable alternative to proprietary APIs.

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 Fable 5 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 (34 models)

1
Claude Mythos 5
Anthropic·Proprietary·1M+

59

sourced avg

2
DeepSeek V4 Pro (Max)
DeepSeek·Open Weight·1M

57.9

sourced avg

3
DeepSeek V4 Pro Base
DeepSeek·Open Weight·1M

55.2

sourced avg

4
Muse Spark 1.1
Meta·Proprietary·1M

52.2

sourced avg

5
Sakana Fugu-Ultra
Sakana AI·Proprietary·1M

50

sourced avg

6
Claude Opus 4.8
Anthropic·Proprietary·1M

49.8

sourced avg

7
Sakana Fugu
Sakana AI·Proprietary·1M

47.2

sourced avg

8
Claude Opus 4.7 (Adaptive)
Anthropic·Proprietary·1M

46.9

sourced avg

9
DeepSeek V4 Pro (High)
DeepSeek·Open Weight·1M

46.2

sourced avg

10
Gemini 3.1 Pro
Google·Proprietary·1M

45.4

sourced avg

11
DeepSeek V4 Pro
DeepSeek·Open Weight·1M

45

sourced avg

12
Kimi K3
Moonshot AI·Pending·1.05M

43.5

sourced avg

13
Claude Sonnet 5
Anthropic·Proprietary·1M

43.2

sourced avg

14
GPT-5.5 Pro
OpenAI·Proprietary·1M

43.1

sourced avg

15
Muse Spark
Meta·Proprietary·262K

42.8

sourced avg

16
GPT-5.4 Pro
OpenAI·Proprietary·1.05M

42.7

sourced avg

17
GPT-5.5
OpenAI·Proprietary·1M

41.4

sourced avg

18
GLM-5.2
Z.AI·Open Weight·1M

40.5

sourced avg

19
Claude Opus 4.6
Anthropic·Proprietary·1M

40

sourced avg

20
GPT-5.4
OpenAI·Proprietary·1.05M

39.8

sourced avg

21
DeepSeek V4 Flash (Max)
DeepSeek·Open Weight·1M

34.1

sourced avg

22
MiMo-V2.5-Pro
Xiaomi·Proprietary·1M

34

sourced avg

23
Grok 4.20
xAI·Proprietary·2M

31.6

sourced avg

24
MAI-Thinking-1
Microsoft·Proprietary·256K

31

sourced avg

25
DeepSeek V4 Flash Base
DeepSeek·Open Weight·1M

30.1

sourced avg

26
Inkling
Thinking Machines Lab·Open Weight·1M

30

sourced avg

27
DeepSeek V4 Flash (High)
DeepSeek·Open Weight·1M

28.9

sourced avg

28
GPT-5.4 mini
OpenAI·Proprietary·400K

28.2

sourced avg

29
Nemotron 3 Ultra
NVIDIA·Open Weight·1M

26.7

sourced avg

30
GPT-5.4 nano
OpenAI·Proprietary·400K

24.3

sourced avg

31
DeepSeek V4 Flash
DeepSeek·Open Weight·1M

23.1

sourced avg

32
Gemma 4 31B
Google·Open Weight·256K

19.5

sourced avg

33
Gemma 4 26B A4B
Google·Open Weight·256K

8.7

sourced avg

34
Gemma 4 12B
Google·Open Weight·256K

5.2

sourced avg

Key Takeaways

The top model on this sourced reporting-family slice is Claude Mythos 5 by Anthropic with an average of 59.

The best open-weight model is DeepSeek V4 Pro (Max) at position #2.

34 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: July 23, 2026

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