April 2026 newsletter
Simon Willison’s Weblog
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4th May 2026
I just sent out the April edition of my sponsors-only monthly newsletter. If you are a sponsor (or if you start a sponsorship now) you can access it here.
In this month's newsletter:
Opus 4.7 and GPT-5.5, both with price increases
Claude Mythos and LLM security research
ChatGPT Images 2.0
More model releases
Other highlights from my blog
What I'm using, April 2026 edition
Here's a copy of the March newsletter as a preview of what you'll get. Pay $10/month to stay a month ahead of the free copy!
Posted 4th May 2026 at 10:38 pm
Recent articles
LLM 0.32a0 is a major backwards-compatible refactor - 29th April 2026
Tracking the history of the now-deceased OpenAI Microsoft AGI clause - 27th April 2026
DeepSeek V4 - almost on the frontier, a fraction of the price - 24th April 2026
This is a note by Simon Willison, posted on 4th May 2026.
newsletter 18
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