Anthropic/Text & chat/Tuesday, August 5, 2025

Claude Opus 4.1

Key facts

Released: Aug 5, 2025
What it does: Text and chat: Writes, answers questions and holds a conversation.Code: Writes, explains and fixes code.Thinks first: Can reason step by step before it answers: slower, but better at maths, code and tricky questions.Sees images: Understands pictures, screenshots and charts you share with it.Reads files: Reads documents such as PDFs.

How: For developers, through an API
Announced as: “Claude Opus 4.1”

From trckr's archive of releases before it started watching. Date and details from Epoch AI's database of AI models (CC BY 4.0).

Price and limits

What developers pay to use it through the API: How developers plug a model into their own apps and pay per use. A model that's "in the API" can be used by programmers, even if it isn't in a chat app yet., per million Tokens: The small chunks of text a model reads and writes, about three-quarters of a word each. Prices and limits are counted in tokens. sent (input) or written back (output), and how much it can take in at once.

Input: $15.00; per million tokensCached: $1.50
Output: $75.00; per million tokens
Context window: How much a model can keep in mind at once: your question, any files you share and its own replies. Measured in tokens; 1,000 tokens is about 750 words.: 200K tokens; about 150,000 words