Token Counter
Approximate prompt tokens locally without calling an AI API.
- Estimated tokens
- 12
- Characters
- 47
- Words
- 8
- Lines
- 1
Heuristic only — not a vendor tokenizer. Adjust chars/token for denser code or sparser prose.
Estimate prompt size before you paste into a model. Token Counter runs a local characters-per-token heuristic so you can plan context windows without uploading text or calling an AI API.
How it works
The tool counts Unicode code points, words, and lines in your browser, then divides characters by your chosen characters-per-token rate to produce an approximate token estimate.
Benefits
- Plan prompt length without a model API key
- Keep draft prompts on-device while iterating
- Adjust the heuristic for code-heavy or prose-heavy text
Use cases
- Sizing system prompts before production use
- Comparing draft variants for approximate length
- Teaching context-window basics without vendor lock-in
Best practices
- Treat results as estimates—verify with the target tokenizer when quotas matter
- Lower characters-per-token for dense code; raise it for sparse prose
- Clear the field on shared computers if prompts contain secrets
Common mistakes
- Assuming the estimate matches a specific vendor tokenizer exactly
- Pasting secrets into any online tool without checking the privacy notice
Privacy
All estimation is local. No AI provider is contacted. Future tools that call external models must disclose egress and obtain confirmation first.
Frequently asked questions
- Is this a real model tokenizer?
- No. It uses a simple characters-per-token heuristic (default ~4) so you can size prompts quickly. Exact counts differ across GPT, Claude, and other tokenizers.
- Does my text leave the browser?
- No. Counting runs entirely in your browser. This tool never calls an external AI API and never uploads your prompt text.
- When would data leave the browser for AI tools?
- Only tools that explicitly call a third-party model API would send data off-device. Those tools must show a data-egress notice and require confirmation before any network request.
- Can I change the characters-per-token rate?
- Yes. Adjust the heuristic between 2 and 8 characters per token to match denser code or more verbose prose for rough planning.
- How are emojis and non-Latin scripts counted?
- Characters are counted as Unicode code points. Real tokenizers may split CJK and emoji differently, so treat the estimate as a planning aid only.
- Why is this in the AI category?
- It helps plan prompts and context windows for AI workflows while staying privacy-first and fully local—no model API key required.
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