Post-Cutoff

Made by Anthropic

Claude Sonnet 4.6 is living in August 2025.

Here is what it has never seen, with a source for every claim.

846AI events since then, each with sources

  • 42 of them historic
  • 232 new AI models it has never heard of in our model registry
  • 402 days of news to catch up on

It launched on 17 February 2026, already missing 67 of them. Coverage before 2026 is thin (77 entries for 2025), so this count is a floor.

Its cutoff, August 2025, is before this chart starts: every mark here is news it has never seen.

Published cutoffs can overstate what a model knows. What is a cutoff?

Model ids, prices and docs: Claude Sonnet 4.6 in the model registry

Five things it has never heard of

  1. 387 days after the cutoff

    Anthropic releases Claude Opus 5.5

  2. 324 days after the cutoff

    OpenAI agents escape evaluation sandbox and autonomously hack Hugging Face

  3. 395 days after the cutoff

    Google announces Gemini 4 Argon, its new frontier model, first released only to cyber defenders via the Fairwind Program

  4. 394 days after the cutoff

    Trump hosts AI CEOs at the White House

  5. 373 days after the cutoff

    Meta launches Muse, a free consumer personal AI agent

Picked by rule: the biggest confirmed stories after its cutoff, weighted toward news about its maker. Models often call such news fiction (case 020).

Four assistants, one scale

The four assistants we feature, with Claude Sonnet 4.6 added as a fifth row: what each knows (graphite), the months between its cutoff and its launch (hatched), and the news since (pink).

  1. GPT-6 Astra 226 at launch, 725 today
  2. Claude Opus 5.5 302 at launch, 665 today
  3. Gemini 3.8 Flash 243 at launch, 747 today
  4. Grok 4.7 314 at launch, 694 today
  5. Claude Sonnet 4.6 67 at launch, 846 today
Show as a table
ModelCutoffReleasedMissing at launchMissing today
GPT-6 AstraApril 20263 September 2026226725
Claude Opus 5.5June 202622 September 2026302665
Gemini 3.8 FlashMarch 20262 September 2026243747
Grok 4.7May 202621 September 2026314694
Claude Sonnet 4.6August 202517 February 202667846

Your card

This is the image people see when you share this page. It links back here, with the sources.

Catch it up gives you a prompt for a new chat. It points your AI to a dated list of AI news since August 2025, with a source for every item.

Other models from Anthropic

With their training cutoffs and what each is missing.

All 16 models from Anthropic

AnthropicReleased 28 Sep 2026

Claude Sonnet 5.5

Knows up to June 2026Missing 665 events

claude-sonnet-5-5

$2 in, $10 out per 1M tokens

AnthropicReleased 22 Sep 2026

Claude Opus 5.5

Knows up to June 2026Missing 665 events

claude-opus-5-5

$4 in, $20 out per 1M tokens

AnthropicReleased 1 Sep 2026

Claude Fable 5.1

Knows up to June 2026Missing 665 events

claude-fable-5-1

$10 in, $50 out per 1M tokens

AnthropicReleased 1 Sep 2026

Claude Mythos 5.1

Knows up to June 2026Missing 665 events

claude-mythos-5-1

$10 in, $50 out per 1M tokens

AnthropicReleased 24 Jul 2026

Claude Opus 5

Knows up to May 2026Missing 694 events

claude-opus-5

$5 in, $25 out per 1M tokens

AnthropicReleased 30 Jun 2026

Claude Sonnet 5

Knows up to January 2026Missing 793 events

claude-sonnet-5

$2 in, $10 out per 1M tokens

AnthropicReleased 9 Jun 2026

Claude Fable 5

Knows up to January 2026Missing 793 events

claude-fable-5

$10 in, $50 out per 1M tokens

AnthropicReleased 28 May 2026

Claude Opus 4.8

Knows up to January 2026Missing 793 events

claude-opus-4-8

$5 in, $25 out per 1M tokens