Prompt Token Counter — See Exactly What GPT-4o and Claude Will Charge You
Live token counts, pricing estimates, and context remaining for GPT-4o, GPT-4, GPT-3.5, GPT-4o mini, Claude, and Gemini
No signup • Runs in browser • Free
LLM prompts balloon quickly, especially when you paste log files, code snippets, or whole PR descriptions. Copy/pasting into a playground just to see a token count wastes time and leaks sensitive text. The Prompt Token Counter keeps everything client-side with js-tiktoken so your prompt never leaves the browser.
Tokenisers covered
| Model | Encoding | Context window | Pricing baseline |
| --- | --- | --- | --- |
| GPT-4o | cl100k_base | 128K tokens | $0.005 / 1K input tokens |
| GPT-4 | cl100k_base | 8,192 tokens | $0.03 / 1K tokens |
| GPT-3.5 Turbo | cl100k_base | 16K tokens | $0.001 / 1K tokens |
| GPT-4o mini | o200k_base | 200K tokens | $0.0005 / 1K tokens |
| Claude (approx) | cl100k_base proxy | 200K tokens | $0.003 / 1K tokens |
| Gemini (approx) | cl100k_base proxy | 1M tokens | $0.0035 / 1K tokens |
Claude and Gemini use cl100k-based proxies so you still get a realistic token ballpark while Anthropic and Google keep their official BPEs closed.
What you see while typing
- Token, character, and word counts update every 100 ms as you edit.
- Estimated spend per model uses current public pricing with a quick link to the vendor's pricing page.
- Context remaining + progress bar shows whether you're safe, approaching the 75% warning zone (amber), or bursting the limit (red).
- Split into chunks proposes how many segments you need at ~80% fill if you exceed a model's window.
- Copy token count instantly copies a model's token total for commit messages, PR templates, or Slack updates.
Everything runs in the browser via WASM — no telemetry, no external API calls, and no prompt leakage.
Workflow ideas
- Preflight every long-form prompt. Paste the doc, note the cheapest model that still fits, and flag any wrap-around chunking before handing it to your team.
- Budget multi-model flows. Compare GPT-4o and GPT-4o mini pricing in the same view to decide which step of your pipeline can downshift.
- Keep CI chatbots on budget. Combine the Token Counter with the Diff Checker so that your PR bot can point to exact token costs when reviewers complain.
- Share links with state. The tool URL encodes the textarea content, so you can paste a link in Slack and everyone opens the same tokenizer snapshot instantly.
Need to double-check a mega prompt right now? Open the Prompt Token Counter, paste your text, and keep those GPT invoices predictable.