Terms

Using the site

Resend Cost is provided free of charge, with no account and no registration. You may use it for personal or commercial work, including analysing traces from your employer's systems, as long as you are entitled to open those files yourself.

The analysis runs entirely in your browser, so you are not sending us anything and we are not processing anything on your behalf. See Privacy for what that means in detail.

The numbers are an estimate, and here is exactly how

This matters more than the rest of this page, so it is stated plainly rather than buried in a disclaimer:

• Prices change without notice. The rate table is hand-maintained from each vendor's published pricing page and carries the date it was verified. The site shows you how old that is. It will eventually be wrong, and it will be wrong before we notice.
• Claude and Gemini figures from a chat export are estimated, because no current local tokenizer exists for either. They are labelled on the page. Do not budget on them.
• Reconstructed traces assume the whole history was re-sent every turn. That is the stateless default and it is wrong for a client that truncates, summarises or caches. If yours does, the figure will be too high — use a request log instead.
• A switch-model figure is a price difference, not a recommendation. A different model will not emit the same number of output tokens, and a cheaper one that needs two attempts is not cheaper.
• Nothing here is your actual invoice. Your bill will include rate tiers, service tiers, tool calls, regional uplifts, free-tier allowances, credits and taxes that this site cannot see, because they are not in your trace. Check your provider's billing console before making a decision that costs money.
• A repeated agent step is not automatically waste. The Claude Code audit proves identical adjacent tool signatures, but pagination, polling and read-after-write can be legitimate. Recovery and suspected-loop dollars are kept separate and require review.
• A structural cache divergence is not proof of provider eviction. The cache lab can show where the local request prefix changed and where a published TTL expired. It cannot observe an undocumented provider eviction or cache policy.

The site is offered as-is, without warranty of any kind. We are not liable for decisions made on the basis of these figures, or for any loss arising from using or being unable to use the site.

Availability

We may change, interrupt or discontinue the site at any time. Because everything runs locally, an outage costs you access to the page and nothing else — there is no data of yours to lose.

Content and licences

The site's text and design are ours. The tokenizer it ships is gpt-tokenizer under the MIT licence, which includes byte-pair-encoding data ported from OpenAI's tiktoken, also MIT; both copyright notices travel with the code, at /vendor/gpt-tokenizer/THIRD-PARTY-NOTICES.md.

Model names and prices belong to the vendors named beside them and are referenced for identification and comparison. This site is not affiliated with, endorsed by or connected to OpenAI, Anthropic or Google.

Contact

support@resendcost.com. If you have found a figure you believe is wrong, please say which one and what you think it should be — a correction with a source attached is the most useful message this address can receive.

Last updated 14 August 2026.