Simon Willison’s Weblog
ttok is my CLI tool for counting tokens, using OpenAI's open source tiktoken library.
It hasn't been in updated in a couple of years, but I finally fixed a Click warning, updated CI, and added a --list-models command to list available models.
It works with uvx , so you can count tokens in anything like this:
cat file.txt | uvx ttok
Recent articles
A new feature for my blog, built using my voice - 9th October 2026
Claude Haiku 5.5 - 7th October 2026
We're going to need default hard budget caps on pretty much everything - 3rd October 2026
OpenAI DevDay 2026 live blog - 29th September 2026
This is a beat by Simon Willison, posted on 8th October 2026 .
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