WhichAI.today

Best AI for fact-checking a claim right now

Updated Oct 25, 2026. Checked daily.

Paste the claim and ask what would confirm it and what would refute it.

The search board measures search answers, not a formal fact-check.

Try this prompt

Check this claim. Name a source that supports it, a source that disputes it, and what is still unknown.

Do not treat the model's verdict as the last word. Read the sources.

#1 Champion

GPT-5.6 Sol

OpenAI

ChatGPT with search, and select GPT-5.6 Sol.

Paid plan

Close race

Leads the public board for models that search the web.

LMArena Search 1261.

Open OpenAI
Details
Why it leads
LMArena Search 1261. Source.
Cost
Uses a ChatGPT plan. Check the plan page for the current price.
Free tier
A free plan may include limited search.
Privacy default
Yes on personal Free, Plus, and Pro. Improve the model for everyone is on by default. Settings, Data controls, turn off Improve the model for everyone. Source
When not to use it
Skip it when you need a citation you can open and the answer does not show one.
Starter prompt
Research this question. Name each source you used, and say what it does not answer.

Top Alternative

Claude Opus 4.6

Anthropic

Claude with web search, and select Opus 4.6.

Paid plan

A top search model from another provider on the same board.

LMArena Search 1251.

Open Anthropic
Details
Why it leads
LMArena Search 1251. Source.
Cost
Uses a Claude plan. Check the plan page for the current price.
Free tier
A free plan may include limited search.
Privacy default
Anthropic says Free, Pro, and Max chats are used for training only if you allow it, and you choose at signup. The toggle has been reported as on by default, so check it. Settings, then Privacy. Turn off Help improve Claude. Source
When not to use it
Skip it if you need the single highest score on the search board.
Starter prompt
Research this question. Separate what the sources say from what is still unknown.

Best Open Source

Diffbot-Small-XL

Diffbot

Diffbot, or the published weights for Diffbot-Small-XL on Hugging Face.

Free (limited)

The open-weights model with a public score on the search board.

LMArena Search 1023. Apache 2.0 weights.

Open Diffbot
Details
Why it leads
LMArena Search 1023. Apache 2.0 weights. Source.
Cost
The weights are under Apache 2.0. A hosted search API may be paid.
Free tier
The weights are free to download.
Privacy default
Privacy default not checked for this provider yet.
When not to use it
Skip it when you need the top of the search board.
Starter prompt
Find sources for this question and list what each one says.

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