AI Model Release Timeline — LLM Launch Dates

This timeline is a hand-verified dataset of 42notable model launches, plus one small piece of arithmetic: how long ago each one shipped. Release dates are not estimated or scraped — every entry stores the date its developer published on launch day, together with a link to that announcement (OpenAI, Anthropic, Google DeepMind, Meta, Mistral, DeepSeek, Alibaba's Qwen team, and xAI).

The only computed value is elapsed time, and it is done two independent ways so the figure can be trusted:

1. Days since release. Both the launch date and today are pinned to UTC midnight, then the difference in milliseconds is divided by 86,400,000 and floored: daysSince = floor((today − release) / 86,400,000). Using UTC on both sides means timezones and daylight-saving changes can never nudge the count by a day.
2. Cross-check by Julian Day Number. The same gap is recomputed with integer Julian Day Number arithmetic (the Fliegel–Van Flandern algorithm), which shares no code with the millisecond method. If the two results ever disagreed, the day count would be suppressed rather than shown wrong.
3. Approximate years.The raw day count is divided by 365.25 — the average calendar year including leap days — and rounded to one decimal for the “~3.3y” style figure.
4. Human phrasing.“3 years, 3 months ago” is built by calendar stepping: whole years are subtracted first, then whole months, borrowing the correct number of days from the previous month (28, 29, 30 or 31) so the label matches how people actually say dates. The exact day count stays untouched.

Filters are plain set logic over the same data. Choosing two developers shows models from either; adding a year narrows to launches in that year as well; the search box matches any part of a model name or its maker. The per-year chips are a group-by count of whatever is currently filtered, and they double as one-tap year filters.

All three are reconciled by hand against a fixed reference date of 8 July 2026. The live tool uses your browser's current date instead, so its numbers grow by one each day.

Release dates are facts each developer published on launch day. Primary announcement hubs:

• OpenAI — news & announcements
• Anthropic — news (Claude)
• Google — The Keyword, AI (Gemini)
• Meta AI — blog (Llama)
• Mistral AI — news
• DeepSeek — news
• Alibaba Qwen — blog
• xAI — news (Grok)

Each timeline card also links to its own source. The full dataset was last cross-checked against these announcements on 2026-07-08 and is reviewed whenever a major model ships.