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Reference

AI model knowledge cutoff dates

A model’s knowledge cutoff is the last date its training data reliably covers; anything published after it, the model doesn’t know. Below are the cutoffs of 40 models people code with, each taken from the vendor’s own docs and linked. The most recent is June 2026 (Claude Fable 5.1, Claude Haiku 5.5, Claude Opus 5.5 and Claude Sonnet 5.5); the oldest still listed is October 1, 2023 (GPT-4o).

Showing 40 of 40 models.

AI model knowledge cutoff dates, with each vendor’s source
Source
Claude Fable 5.1AnthropicJun 2026Reliable knowledge cutoff4 months agoAnthropic docs for Claude Fable 5.1 (opens in a new tab)Reliable knowledge cutoff
Claude Haiku 5.5AnthropicJun 2026Reliable knowledge cutoff4 months agoAnthropic docs for Claude Haiku 5.5 (opens in a new tab)Reliable knowledge cutoff
Claude Opus 5.5AnthropicJun 2026Reliable knowledge cutoff4 months agoAnthropic docs for Claude Opus 5.5 (opens in a new tab)Reliable knowledge cutoff
Claude Sonnet 5.5AnthropicJun 2026Reliable knowledge cutoff4 months agoAnthropic docs for Claude Sonnet 5.5 (opens in a new tab)Reliable knowledge cutoff
Claude Opus 5LegacyAnthropicMay 2026Reliable knowledge cutoff5 months agoAnthropic docs for Claude Opus 5 (opens in a new tab)Reliable knowledge cutoff
Grok 4.7xAIMay 2026Knowledge cut-off date5 months agoxAI docs for Grok 4.7 (opens in a new tab)Knowledge cut-off date
GPT-6 LunaOpenAIMay 18, 2026Knowledge cutoff5 months agoOpenAI API docs for GPT-6 Luna (opens in a new tab)Knowledge cutoff
GPT-6 AstraOpenAIApr 30, 2026Knowledge cutoff6 months agoOpenAI API docs for GPT-6 Astra (opens in a new tab)Knowledge cutoff
GPT-6.1 SolOpenAIApr 30, 2026Knowledge cutoff6 months agoOpenAI API docs for GPT-6.1 Sol (opens in a new tab)Knowledge cutoff
GPT-6 SolOpenAIApr 20, 2026Knowledge cutoff6 months agoOpenAI API docs for GPT-6 Sol (opens in a new tab)Knowledge cutoff
Gemini 3.8 FlashGoogleMar 2026Knowledge cutoff date7 months agoGoogle model card for Gemini 3.8 Flash (opens in a new tab)Knowledge cutoff date
Gemini 4 ArgonGoogleMar 2026Knowledge cutoff7 months agoGoogle model card for Gemini 4 Argon (opens in a new tab)Knowledge cutoff
GPT-5.6 SolOpenAIFeb 16, 2026Knowledge cutoff8 months agoOpenAI API docs for GPT-5.6 Sol (opens in a new tab)Knowledge cutoff
Claude Fable 5LegacyAnthropicJan 2026Reliable knowledge cutoff9 months agoAnthropic docs for Claude Fable 5 (opens in a new tab)Reliable knowledge cutoff
Claude Opus 4.7LegacyAnthropicJan 2026Reliable knowledge cutoff9 months agoAnthropic docs for Claude Opus 4.7 (opens in a new tab)Reliable knowledge cutoff
Claude Opus 4.8LegacyAnthropicJan 2026Reliable knowledge cutoff9 months agoAnthropic docs for Claude Opus 4.8 (opens in a new tab)Reliable knowledge cutoff
Claude Sonnet 5LegacyAnthropicJan 2026Reliable knowledge cutoff9 months agoAnthropic docs for Claude Sonnet 5 (opens in a new tab)Reliable knowledge cutoff
Grok 4.6xAIJan 2026Pretraining data cutoff9 months agoxAI model card for Grok 4.6 (opens in a new tab)Pretraining data cutoff
MAI-Code-1.1-FlashMicrosoftDec 2025Pretraining cut-off date10 months agoMicrosoft model card for MAI-Code-1.1-Flash (opens in a new tab)Pretraining cut-off date
GPT-5.5OpenAIDec 1, 2025Knowledge cutoff10 months agoOpenAI API docs for GPT-5.5 (opens in a new tab)Knowledge cutoff
Claude Sonnet 4.6LegacyAnthropicAug 2025Reliable knowledge cutoff1 year and 2 months agoAnthropic docs for Claude Sonnet 4.6 (opens in a new tab)Reliable knowledge cutoff
GPT-5.3-CodexDeprecatedOpenAIAug 31, 2025Knowledge cutoff1 year and 2 months agoOpenAI API docs for GPT-5.3-Codex (opens in a new tab)Knowledge cutoff
GPT-5.4OpenAIAug 31, 2025Knowledge cutoff1 year and 2 months agoOpenAI API docs for GPT-5.4 (opens in a new tab)Knowledge cutoff
GPT-5.4 MiniOpenAIAug 31, 2025Knowledge cutoff1 year and 2 months agoOpenAI API docs for GPT-5.4 Mini (opens in a new tab)Knowledge cutoff
Claude Opus 4.5LegacyAnthropicMay 2025Reliable knowledge cutoff1 year and 5 months agoAnthropic docs for Claude Opus 4.5 (opens in a new tab)Reliable knowledge cutoff
Claude Opus 4.6LegacyAnthropicMay 2025Reliable knowledge cutoff1 year and 5 months agoAnthropic docs for Claude Opus 4.6 (opens in a new tab)Reliable knowledge cutoff
Claude Haiku 4.5LegacyAnthropicFeb 2025Reliable knowledge cutoff1 year and 8 months agoAnthropic docs for Claude Haiku 4.5 (opens in a new tab)Reliable knowledge cutoff
Claude Sonnet 4.5DeprecatedAnthropicJan 2025Reliable knowledge cutoff1 year and 9 months agoAnthropic docs for Claude Sonnet 4.5 (opens in a new tab)Reliable knowledge cutoff
Gemini 2.5 FlashGoogleJan 2025Knowledge cutoff1 year and 9 months agoGoogle docs for Gemini 2.5 Flash (opens in a new tab)Knowledge cutoff
Gemini 2.5 ProGoogleJan 2025Knowledge cutoff1 year and 9 months agoGoogle docs for Gemini 2.5 Pro (opens in a new tab)Knowledge cutoff
Gemini 3 FlashPreviewGoogleJan 2025Knowledge cutoff1 year and 9 months agoGoogle docs for Gemini 3 Flash (opens in a new tab)Knowledge cutoff
Gemini 3.1 ProPreviewGoogleJan 2025Knowledge cutoff1 year and 9 months agoGoogle docs for Gemini 3.1 Pro (opens in a new tab)Knowledge cutoff
GPT-5DeprecatedOpenAISep 30, 2024Knowledge cutoff2 years and 1 month agoOpenAI API docs for GPT-5 (opens in a new tab)Knowledge cutoff
GPT-5-CodexRetiredOpenAISep 30, 2024Knowledge cutoff2 years and 1 month agoOpenAI API docs for GPT-5-Codex (opens in a new tab)Knowledge cutoff
GPT-5.1DeprecatedOpenAISep 30, 2024Knowledge cutoff2 years and 1 month agoOpenAI API docs for GPT-5.1 (opens in a new tab)Knowledge cutoff
Llama 4 MaverickMetaAug 2024Knowledge cutoff2 years and 2 months agoMeta model card for Llama 4 Maverick (opens in a new tab)Knowledge cutoff
GPT-4.1DeprecatedOpenAIJun 1, 2024Knowledge cutoff2 years and 4 months agoOpenAI API docs for GPT-4.1 (opens in a new tab)Knowledge cutoff
o3DeprecatedOpenAIJun 1, 2024Knowledge cutoff2 years and 4 months agoOpenAI API docs for o3 (opens in a new tab)Knowledge cutoff
GPT-5 MiniDeprecatedOpenAIMay 31, 2024Knowledge cutoff2 years and 5 months agoOpenAI API docs for GPT-5 Mini (opens in a new tab)Knowledge cutoff
GPT-4oDeprecatedOpenAIOct 1, 2023Knowledge cutoff3 years agoOpenAI API docs for GPT-4o (opens in a new tab)Knowledge cutoff

Each date is the vendor’s own, in the vendor’s own terms, checked against its docs; last checked . Models are listed only when the vendor publishes a cutoff.

Why the cutoff matters for code

A model knows the packages, versions and vulnerabilities that existed when its training data was collected. Anything published later is invisible to it unless a tool hands it live data: a CVE disclosed last month, a release line that reached end of life, a major version with breaking changes. It still answers, confidently, with the versions it remembers.

See what that means for one model: everything that changed since Claude Sonnet 4.5’s cutoff, each item linked to CISA, GitHub or endoflife.date. Or read it month by month in What your agent missed.

How each vendor states it

Anthropic
Two dates per model. The reliable knowledge cutoff is “the date through which the model’s knowledge is most extensive and reliable”; the training data cutoff is the broader range of data used. Both are on each model’s docs page.
OpenAI
One knowledge cutoff per model, to the day, on each model’s page in the API docs.
Google
A month, in the Gemini API docs or the model cards. For recent Gemini models Google adds that in some domains the knowledge may stop earlier.