New: Claude Fable 5.2 eval report is here.Read the report ↗
Compare models

Pace of Progress

Model releases from three leading AI labs: Anthropic, OpenAI and Google, from January 2025 through November 9, 2026, including frontier models (e.g. Fable 5.2) and cost-effective models (e.g. GPT-6.1 Terra).

Updated November 9, 2026
Anthropic
2.6×
as many release days

5 in 2025 → 13 in 2026

036912151132639Nov 9Week of year
OpenAI
1.8×
as many release days

5 in 2025 → 9 in 2026

036912151132639Nov 9Week of year
Google
2.0×
as many release days

4 in 2025 → 8 in 2026

036912151132639Nov 9Week of year
Release days through Nov 92026 2025

Model releases

Download data ↓
○ 2025 ◆ 2026

Anthropic

SonnetOpusHaikuFable / Mythos
15913172125293337414549532026Opus 4.6 · Feb 5, 2026 Public launch / previewOpus 4.6Sonnet 4.6 · Feb 17, 2026 Public launch / previewSonnet 4.6Mythos Preview* · Apr 7, 2026 Restricted previewMythos Preview*Opus 4.7 · Apr 16, 2026 Public launch / previewOpus 4.7Opus 4.8 · May 28, 2026 Public launch / previewOpus 4.8Fable / Mythos 5 · Jun 9, 2026 Fable public; Mythos restricted Same underlying Fable/Mythos model counted once; no repeat for redeployment.Fable / Mythos 5Sonnet 5 · Jun 30, 2026 Public launch / previewSonnet 5Opus 5 · Jul 24, 2026 Public launch / previewOpus 5Fable / Mythos 5.1 · Sep 1, 2026 Fable public; Mythos restricted Official model overview and release notes identify September 1, 2026. Corrected the earlier September 15 announcement-date transcription.Fable / Mythos 5.1Opus 5.5 · Sep 22, 2026 Public launch / previewOpus 5.5Sonnet 5.5 · Sep 28, 2026 Public launch / previewSonnet 5.5Haiku 5.5 · Oct 7, 2026 Public launch / previewHaiku 5.5Fable / Mythos 5.2 · Nov 9, 2026 Fable public; Mythos restricted Same underlying Fable/Mythos model counted once; no repeat for redeployment.Fable / Mythos 5.22025Sonnet 3.7 · Feb 24, 2025 Public launch / previewSonnet 3.7Opus 4 · May 22, 2025 Public launch / previewOpus 4Sonnet 4 · May 22, 2025 Public launch / previewSonnet 4Opus 4.1 · Aug 5, 2025 Public launch / previewOpus 4.1Sonnet 4.5 · Sep 29, 2025 Public launch / previewSonnet 4.5Haiku 4.5 · Oct 15, 2025 Public launch / previewHaiku 4.5Opus 4.5 · Nov 24, 2025 Public launch / previewOpus 4.5

OpenAI

Mini / nanoGPT full / Solo-series fullTerra / LunaAstra
15913172125293337414549532026GPT-5.3 Instant · Mar 3, 2026 Public launch / preview Pro compute variants excluded.GPT-5.3 InstantGPT-5.4 · Mar 5, 2026 Public launch / preview Pro compute variants excluded.GPT-5.4GPT-5.4 mini · Mar 17, 2026 Public launch / preview Pro compute variants excluded.GPT-5.4 miniGPT-5.4 nano · Mar 17, 2026 Public launch / preview Pro compute variants excluded.GPT-5.4 nanoGPT-5.5 · Apr 23, 2026 Public launch / preview Pro compute variants excluded.GPT-5.5GPT-5.6 Sol* · Jun 26, 2026 Restricted initial preview / rollout June 26 limited preview; July 9 broad release not counted again.GPT-5.6 Sol*GPT-5.6 Terra* · Jun 26, 2026 Restricted initial preview / rollout June 26 limited preview; July 9 broad release not counted again.GPT-5.6 Terra*GPT-5.6 Luna* · Jun 26, 2026 Restricted initial preview / rollout June 26 limited preview; July 9 broad release not counted again.GPT-5.6 Luna*GPT-6 Astra* · Sep 3, 2026 Restricted initial preview / rollout Pro compute variants excluded.GPT-6 Astra*GPT-6 Sol · Sep 22, 2026 Public launch / preview Pro compute variants excluded.GPT-6 SolGPT-6 Luna · Sep 22, 2026 Public launch / preview Pro compute variants excluded.GPT-6 LunaGPT-6.1 Sol · Sep 29, 2026 Public launch / preview Pro compute variants excluded.GPT-6.1 SolGPT-6.1 Terra · Oct 26, 2026 Public launch / preview Pro compute variants excluded.GPT-6.1 Terra2025o3-mini · Jan 31, 2025 Public launch / preview Pro compute variants excluded.o3-miniGPT-4.5 · Feb 27, 2025 Public launch / preview Pro compute variants excluded.GPT-4.5GPT-4.1 · Apr 14, 2025 Public launch / preview Pro compute variants excluded.GPT-4.1GPT-4.1 mini · Apr 14, 2025 Public launch / preview Pro compute variants excluded.GPT-4.1 miniGPT-4.1 nano · Apr 14, 2025 Public launch / preview Pro compute variants excluded.GPT-4.1 nanoo3 · Apr 16, 2025 Public launch / preview Pro compute variants excluded.o3o4-mini · Apr 16, 2025 Public launch / preview Pro compute variants excluded.o4-miniGPT-5 · Aug 7, 2025 Public launch / preview Pro compute variants excluded.GPT-5GPT-5 mini · Aug 7, 2025 Public launch / preview Pro compute variants excluded.GPT-5 miniGPT-5 nano · Aug 7, 2025 Public launch / preview Pro compute variants excluded.GPT-5 nanoGPT-5.1 · Nov 12, 2025 Public launch / preview Instant and Thinking grouped under the same numbered release. Pro compute variants excluded.GPT-5.1GPT-5.2 · Dec 11, 2025 Public launch / preview Instant and Thinking grouped under the same numbered release. Pro compute variants excluded.GPT-5.2

GoogleGemini

Pro / frontierFlash-LiteFlash
159131721252933374145495320263.1 Pro · Feb 19, 2026 Public launch / preview Gemini prefix omitted on plot. First named preview used; later GA not recounted.3.1 Pro3.1 Flash-Lite · Mar 3, 2026 Public launch / preview Gemini prefix omitted on plot. First named preview used; later GA not recounted.3.1 Flash-Lite3.5 Flash · May 19, 2026 Public launch / preview Gemini prefix omitted on plot. First named preview used; later GA not recounted.3.5 Flash3.6 Flash · Jul 21, 2026 Public launch / preview Gemini prefix omitted on plot. First named preview used; later GA not recounted.3.6 Flash3.5 Flash-Lite · Jul 21, 2026 Public launch / preview Gemini prefix omitted on plot. First named preview used; later GA not recounted.3.5 Flash-Lite3.7 Flash · Aug 13, 2026 Public launch / preview Gemini prefix omitted on plot. First named preview used; later GA not recounted.3.7 Flash3.8 Flash · Sep 2, 2026 Public launch / preview Gemini prefix omitted on plot. First named preview used; later GA not recounted.3.8 Flash4 Argon* · Sep 30, 2026 Restricted rollout announced Sep 30 restricted rollout; Oct 13 general availability not counted again.4 Argon*4 Carbon* · Oct 28, 2026 Restricted rollout announced Oct 28 announcement; partner access described as starting that week.4 Carbon*20252.0 Pro Experimental · Feb 5, 2025 Public launch / preview Gemini prefix omitted on plot. First named preview used; later GA not recounted.2.0 Pro Experimental2.0 Flash-Lite · Feb 5, 2025 Public launch / preview Gemini prefix omitted on plot. First named preview used; later GA not recounted.2.0 Flash-Lite2.5 Pro · Mar 25, 2025 Public launch / preview Gemini prefix omitted on plot. First named preview used; later GA not recounted.2.5 Pro2.5 Flash · Apr 17, 2025 Public launch / preview Gemini prefix omitted on plot. First named preview used; later GA not recounted.2.5 Flash2.5 Flash-Lite · Jun 17, 2025 Public launch / preview Gemini prefix omitted on plot. First named preview used; later GA not recounted.2.5 Flash-Lite3 Pro · Nov 18, 2025 Public launch / preview Gemini prefix omitted on plot. First named preview used; later GA not recounted.3 Pro3 Flash · Dec 17, 2025 Public launch / preview Gemini prefix omitted on plot. First named preview used; later GA not recounted.3 Flash
Weeks since January 1 · * Restricted accessGray: beyond the 2026 cutoff

Sources

How we count releases

Named, general-purpose models, including previews and restricted launches. First launch announcements only; later rollouts and routine updates are excluded.

One launch day per lab, even when several models arrive together. Both years are compared through November 9. Week 1 begins January 1. Fable/Mythos versions count once.

Release frequency measures shipping cadence. It does not measure gains in intelligence.

Full methodology and date notes ↗