Grok 4.20
Key facts
- Released
- Feb 17, 2026
- What it does
- Text and chat: Writes, answers questions and holds a conversation.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.
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- How
- For developers, through an API
- Size
- Parameters: The numbers a model learns during training: a rough measure of its size. Bigger usually means more capable, but slower and pricier to run. 7B means 7 billion.
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
- $1.25
- per million tokensCached: $0.20
- Output
- $2.50
- 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.
- 1M tokens
- about 750,000 words
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- Longest answer
- 30K tokens (about 23,000 words)
- Over 200K tokens
- $2.50 input, $5.00 output per million tokens
From the lab's own listing on models.dev and OpenRouter, checked .
How it scores
From independent testers, never the lab's own claims.
Compare Grok 4.20 with
It came out 90 days after Grok 4.1 Fast, the lab's previous model.
The details
Model ID: The exact name developers type to use a model, like gpt-5-mini. New IDs often show up in a lab's systems before the official announcement, which is how trckr spots many releases early.
grok-4.20-0309-non-reasoninggrok-4.20-0309-reasoningTimeline
/xAI APIOfficialFirst signal
grok-4.20-0309-non-reasoning
/xAI APIOfficial
grok-4.20-0309-reasoning
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