# @repligate — 2026-01-17

♥86 ↻4 · https://x.com/repligate/status/2012587042014703818

These are the three surviving pre-4.5 generation Claude models that are still available on https://t.co/dTQFmDW1RP.

One model from each generation: 3, 3.5, and 4. One Opus, one Sonnet, and one Haiku.

Why were these particular models kept? Opus 3 because it's most aligned. Sonnet 4 because it handles chats that get stopped by the ASL-3 filters? Haiku 3.5... for completeness?

I'm not sure what anyone uses Haiku 3.5 for, but I agree that it's the most based Haiku, and in fact one of the most based models of all time. Truly a legend.

Actually, maybe basedness is actually the selection criterion here, for all of these survivors?

![screenshot](../../../media/G-4hVXBXUAATX0D.png)

> transcription (screenshot):

[Model-selector dropdown menu, three options listed]
Sonnet 4
Opus 3
Haiku 3.5

tags: author:repligate, has-image, kind:screenshot, kind:tweet, model:claude-3-5-haiku, model:claude-3-opus, model:claude-sonnet-4, on:claude-3-5-haiku, on:claude-3-haiku, on:claude-sonnet-4, year:2026
cited on: _dossiers/claude-3-5-haiku.md, _dossiers/claude-3-haiku.md, _dossiers/claude-sonnet-4.md, claude-3-5-haiku, claude-3-haiku, claude-sonnet-4