Agents tool

Prompt Token Estimator

Get a rough token and context-size estimate for a prompt without transmitting its content.

Free browser tool

No Matrix computer needed

✓ No account or card

✓ Use the result right away

✓ Task-specific limits below

Workspace

Use prompt token estimator

Runs in this browser tab

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Result

Your result will appear here. The input stays in this browser tab.

How to use it

Paste a prompt to estimate its approximate token count using a simple text heuristic.

Try this example

Explain how Matrix keeps agents working when a laptop closes.

What to check

Actual tokenizer counts vary by model and format; use provider metering for billing.

Review the result before using it in a published page, application, or agent configuration.

Quick answers

Frequently asked questions

How does Matrix estimate prompt tokens?

It uses a rough character-based calculation. Actual counts depend on the model tokenizer, language, formatting, and tool messages.

Can I use this estimate to enforce a model limit?

Treat it as an early planning signal. Leave room for system instructions and outputs, then check the actual model or API count.

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