Dev Tools

AI Utilities Tools

Estimate tokens and API cost for common chat models from published tokenizers and price lists. We do not call those APIs with your prompt.

7 tools · 100% browser-based · No uploads · No signup

About these AI Utilities tools

AI utilities estimate tokens, visualize token boundaries, plan context windows, trim prompts, and ballpark API cost for common chat and embedding models. They run locally with published tokenizers and price tables. They do not call OpenAI, Anthropic, or Google on your behalf.

Token counts are estimates of what a given tokenizer would emit. Providers can change tokenizers and prices. Always confirm on the vendor's pricing page before you commit budget. Cost compare is a worksheet, not a contract.

Tools in this category

How these tools run in your browser

Tokenizers (where bundled) run in the browser. Some models use a close sibling tokenizer when the exact one is too large to ship. Prices live in our source and are dated. Context estimator adds system, tools, and history the way typical chat APIs bill, which is still an approximation of each provider's real billing rules.

Common Use Cases

  • See whether a prompt plus history fits an 8k, 32k, or 128k window
  • Trim logs out of a prompt without cutting mid-sentence
  • Compare input/output prices across models for a daily volume
  • Estimate embedding dimensions and storage for a vector DB
  • Explain to a stakeholder why "characters" are not "tokens"

Common Mistakes

A tokenizer mismatch of a few percent is normal across model families.
Cached input, batch APIs, and fine-tuned models change the bill.
Images, audio, and tools have their own token rules not covered by plain text counts.
Prompt trimmer cannot know which paragraph is load-bearing. You still review the cut.

Frequently Asked Questions

Do you send my prompt to a model?

No. Counting and trimming happen on this page. There is no chat completion.

Why does OpenAI's counter disagree by a few tokens?

Different tokenizer builds, special tokens, and chat templates. Use the vendor playground as the source of truth for billing disputes.

How often is pricing updated?

We review provider pages at least monthly. See the editorial policy. Check the last-updated date on the cost tools.