Last updated October 13, 2026
Claude Model Timeline
Every Claude release, dated and sourced.
Anthropic has shipped a lot of Claude models since 2023, and the names, IDs and retirement dates are scattered across years of announcements. This page puts all 31 publicly released models in one table: when each one shipped, the API model ID you would call, the context window Anthropic published, and whether you can still use it. Every row links to the Anthropic page it came from.
The newest Claude model is Claude Haiku 5.5, released October 7, 2026. Anthropic's current lineup is Claude Haiku 5.5, Claude Sonnet 5.5, Claude Opus 5.5 and Claude Fable 5.1, with Claude Mythos 5.1 available to verified organizations. The first public models were Claude 1 and Claude Instant, launched March 14, 2023.
Right now
The current Claude lineup
Claude Sonnet 5.5
CurrentReleased September 28, 2026
claude-sonnet-5-5
1M tokens
Source: platform.claude.comClaude Opus 5.5
CurrentReleased September 22, 2026
claude-opus-5-5
1M tokens
Source: platform.claude.comClaude Mythos 5.1
CurrentReleased September 1, 2026
claude-mythos-5-1
1M tokens · Verification required
Source: platform.claude.comClaude Fable 5.1
CurrentReleased September 1, 2026
claude-fable-5-1
1M tokens
Source: platform.claude.comMarch 14, 2023 to October 7, 2026
Every Claude model, newest first
Release dates are when each model became available. "Not published" means Anthropic did not publish that detail on a page we could verify, so we left it blank rather than guess.
2026
| Model | Released | API model ID | Context window | Status | Source |
|---|---|---|---|---|---|
| Claude Haiku 5.5 | claude-haiku-5-5 | 1M tokens | Current | platform.claude.com | |
| Claude Sonnet 5.5 | claude-sonnet-5-5 | 1M tokens | Current | platform.claude.com | |
| Claude Opus 5.5 | claude-opus-5-5 | 1M tokens | Current | platform.claude.com | |
| Claude Mythos 5.1Verification required | claude-mythos-5-1 | 1M tokens | Current | platform.claude.com | |
| Claude Fable 5.1 | claude-fable-5-1 | 1M tokens | Current | platform.claude.com | |
| Claude Opus 5 | claude-opus-5 | 1M tokens | Legacy | platform.claude.com | |
| Claude Sonnet 5 | claude-sonnet-5 | 1M tokens | Legacy | platform.claude.com | |
| Claude Mythos 5Verification required | claude-mythos-5 | 1M tokens | Legacy | platform.claude.com | |
| Claude Fable 5 | claude-fable-5 | 1M tokens | Legacy | platform.claude.com | |
| Claude Opus 4.8 | claude-opus-4-8 | 1M tokens | Legacy | platform.claude.com | |
| Claude Opus 4.7 | claude-opus-4-7 | 1M tokens | Legacy | platform.claude.com | |
| Claude Sonnet 4.6 | claude-sonnet-4-6 | 1M tokens | Legacy | platform.claude.com | |
| Claude Opus 4.6 | claude-opus-4-6 | 1M tokens | Legacy | platform.claude.com |
2025
| Model | Released | API model ID | Context window | Status | Source |
|---|---|---|---|---|---|
| Claude Opus 4.5 | claude-opus-4-5-20251101alias: claude-opus-4-5 | 200K tokens | Legacy | platform.claude.com | |
| Claude Haiku 4.5 | claude-haiku-4-5-20251001alias: claude-haiku-4-5 | 200K tokens | Legacy | platform.claude.com | |
| Claude Sonnet 4.5 | claude-sonnet-4-5-20250929alias: claude-sonnet-4-5 | 200K tokens | DeprecatedRetires November 30, 2026 | platform.claude.com | |
| Claude Opus 4.1 | claude-opus-4-1-20250805 | Not published | RetiredRetired August 5, 2026 | anthropic.com | |
| Claude Sonnet 4 | claude-sonnet-4-20250514 | 200K tokens (a 1M-token beta was offered from August 12, 2025 until April 30, 2026) | RetiredRetired June 15, 2026 | anthropic.com | |
| Claude Opus 4 | claude-opus-4-20250514 | Not published | RetiredRetired June 15, 2026 | anthropic.com | |
| Claude 3.7 SonnetAlso: Claude Sonnet 3.7 | claude-3-7-sonnet-20250219 | Not published | RetiredRetired February 19, 2026 | anthropic.com |
2024
| Model | Released | API model ID | Context window | Status | Source |
|---|---|---|---|---|---|
| Claude 3.5 HaikuAlso: Claude Haiku 3.5 | claude-3-5-haiku-20241022 | Not published | RetiredRetired February 19, 2026 | platform.claude.com | |
| Claude 3.5 Sonnet (upgraded)Also: Claude Sonnet 3.5 (October 2024) | claude-3-5-sonnet-20241022 | Not published | RetiredRetired October 28, 2025 | anthropic.com | |
| Claude 3.5 SonnetAlso: Claude Sonnet 3.5 | claude-3-5-sonnet-20240620 | 200K tokens | RetiredRetired October 28, 2025 | anthropic.com | |
| Claude 3 HaikuAlso: Claude Haiku 3 | claude-3-haiku-20240307 | 200K tokens | RetiredRetired April 20, 2026 | anthropic.com | |
| Claude 3 SonnetAlso: Claude Sonnet 3 | claude-3-sonnet-20240229 | 200K tokens | RetiredRetired July 21, 2025 | anthropic.com | |
| Claude 3 OpusAlso: Claude Opus 3 | claude-3-opus-20240229 | 200K tokens | RetiredRetired January 5, 2026 | anthropic.com |
2023
| Model | Released | API model ID | Context window | Status | Source |
|---|---|---|---|---|---|
| Claude 2.1 | claude-2.1 | 200K tokens | RetiredRetired July 21, 2025 | anthropic.com | |
| Claude Instant 1.2 | claude-instant-1.2 | Not published | RetiredRetired November 6, 2024 | anthropic.com | |
| Claude 2 | claude-2.0 | 100K tokens | RetiredRetired July 21, 2025 | anthropic.com | |
| Claude Instant 1 | claude-instant-1.0claude-instant-1.1 | Not published | RetiredRetired November 6, 2024 | anthropic.com | |
| Claude 1 | claude-1.0claude-1.1claude-1.2claude-1.3 | 9K tokens at launch, expanded to 100K tokens on May 11, 2023 | RetiredRetired November 6, 2024 | anthropic.com |
Reading the names
How Claude models are named
Most Claude models belong to one of three tiers. Haiku is the fastest, built for high-volume work like classification and routing. Sonnet balances speed and intelligence. Opus is aimed at long-running agentic coding and knowledge work. Since June 2026 there is also Fable, for the most demanding reasoning and long-horizon work, and Mythos, the same model offered only to verified organizations.
The word order changed along the way. Early models put the generation first (Claude 3.5 Sonnet, Claude 3.7 Sonnet). From Claude 4 on, the tier comes first and the version follows (Claude Sonnet 4, Claude Opus 4.8), and Anthropic's docs now refer to older models the same way, such as Claude Sonnet 3.7.
API model IDs changed too. From Claude 3 through the 4.5 generation, IDs ended in a snapshot date, like claude-3-7-sonnet-20250219, often with a shorter alias. From the 4.6 generation on, IDs such as claude-opus-4-6 have no date, but Anthropic notes each one is still a pinned snapshot.
For a plain-English walkthrough of tiers, versions and what you are running in the Claude app, read Anthropic model names explained.
What the status labels mean
Listed in the comparison table on Anthropic's models overview page (or the verification-gated twin of a model listed there).
Still available on the Claude API but no longer in the current lineup. Anthropic lists it as active with no deprecation date yet.
Still works, but Anthropic has announced a retirement date and a recommended replacement.
No longer available on the Claude API. Requests to it fail.
Statuses follow Anthropic's model deprecations page and apply to the Claude API. Amazon Bedrock and Google Cloud set their own retirement schedules.
Use this data
The full timeline is available as a JSON file with every field on this page, plus lifecycle dates and extra sources. It is free to reuse under CC BY 4.0: put it in an article, a model picker, a spreadsheet or a research paper, and credit Nightschool AI with a link back.
Use this data: download JSON (CC BY 4.0, link back to nightschoolai.com)Endpoint
https://nightschoolai.com/api/claude-models
Suggested credit
Claude Model Timeline by Nightschool AI (https://nightschoolai.com/claude-model-timeline), CC BY 4.0
How we verify each row
Every field comes from a page Anthropic publishes: its news announcements on anthropic.com, the models overview, each model's docs page, the deprecations page and the API release notes. Where those pages disagree on a date (for example an announcement published late in the evening US time), we use the API release notes and say so in the row's notes in the JSON.
If we could not confirm a detail on a first-party page, the field is empty. Spot something out of date? Let us know through the contact page.
Independent reference compiled by Nightschool AI from Anthropic's public announcements and documentation. Not affiliated with or endorsed by Anthropic. Claude is a trademark of Anthropic.
Frequently Asked Questions
What is the latest Claude model?
The newest release is Claude Haiku 5.5, released October 7, 2026. Anthropic's current lineup is Claude Haiku 5.5, Claude Sonnet 5.5, Claude Opus 5.5 and Claude Fable 5.1, plus Claude Mythos 5.1 for verified organizations.
How many Claude models has Anthropic released?
This timeline lists 31 publicly released Claude models, starting with Claude 1 on March 14, 2023. 5 are current, 10 are legacy, 1 is deprecated and 15 are retired. Point versions Anthropic never announced separately (such as Claude 1.1 to 1.3) share one row.
What is the difference between Claude Fable and Claude Mythos?
They share the same specifications. Anthropic describes Claude Mythos 5 as the same underlying model as Claude Fable 5 with some safeguards lifted, and Claude Mythos 5.1 as offering the same capabilities as Claude Fable 5.1. Fable is open to all API customers; Mythos is available only to organizations verified through Anthropic's programs, such as the Cyber Verification Program.
What do current, legacy, deprecated and retired mean?
Current models are the ones in the comparison table on Anthropic's models overview. Legacy models still work and have no retirement date yet. Deprecated models still work, but Anthropic has set a retirement date and named a replacement. Retired models no longer respond to API requests. Dates apply to the Claude API; Amazon Bedrock and Google Cloud set their own schedules.
Which Claude models have a 1M token context window?
Per Anthropic's docs: Claude Opus 4.6, Claude Sonnet 4.6, Claude Opus 4.7, Claude Opus 4.8, Claude Fable 5, Claude Mythos 5, Claude Sonnet 5, Claude Opus 5, Claude Fable 5.1, Claude Mythos 5.1, Claude Opus 5.5, Claude Sonnet 5.5 and Claude Haiku 5.5. Earlier models such as Claude Opus 4.5, Claude Sonnet 4.5 and Claude Haiku 4.5 have a 200K token window.
Why is Claude Mythos Preview not on the timeline?
Anthropic described Claude Mythos Preview as an unreleased model when it announced Project Glasswing on April 7, 2026, and offered it only to partner organizations doing defensive security work. Its API ID, claude-mythos-preview, appears on the deprecations page as deprecated on June 9, 2026. This timeline only lists models that were publicly released.
Can I use this data on my own site?
Yes. The dataset is free to reuse under CC BY 4.0. Download the JSON, use it in articles, tools or research, and credit Nightschool AI with a link to nightschoolai.com/claude-model-timeline.
How often is this timeline updated?
We update it when Anthropic launches, deprecates or retires a model, checking every field against Anthropic's own announcement and documentation pages. It was last updated on October 13, 2026.