Writing tools · model-cost literacy
HeroChí
Sharpen every word
Give writers immediate text feedback and make token-budget assumptions visible.
- Source private
- Live
My role: Product design, browser-based analyzers, interface, and operation.
- Live product
- Client-side
- AI token analytics
At a glance
- Problem
- Writers and prompt authors need instant text analysis, and nobody wants to paste draft copy into someone else's server.
- My contribution
- Product design, browser-based analyzers, interface, and operation: twelve writing tools, from readability and keyword density to prompt budgeting, with the token counter separating named local encodings from rough provider estimates.
- Outcome
- A live product I operate end to end, and a working piece of model-cost literacy: budgets reserve input and output context independently and label their historical cost assumptions.
Engineering decisions
01
Keep draft text local
Readability, word statistics, keyword density, and token analysis run in the browser. These tools do not need a text-processing backend.
02
Distinguish tokens from words
Supported OpenAI entries use the explicitly named o200k_base encoder, including whitespace and literal token spellings. Other providers are labeled unvalidated ratio estimates, with no invented accuracy band.
Tradeoff
Naming one real encoder and labeling the rest as estimates is less impressive than a universal counter and does not pretend to an accuracy the tool cannot check.
03
Expose the cost assumptions
Pasted text, other input context, and an output reservation form a visible budget. Overages remain visible beyond 100%. Costs use an explicitly unverified April 2026 project snapshot; a derived-only report carries the assumptions without exporting the prompt.
What you can verify
- Live writing tools with immediate browser-side feedback.
- Inspect the selected token method and the assumptions behind any cost estimate.
- Compare prose, code, non-English text, and a budget that exceeds the selected context limit.
Source and release links checked .
Scope and limits
Readability formulas are indicators, not an assessment of a writer's ability. Token and cost estimates have model-specific limits and do not replace a provider's billed usage.
A short walkthrough
- 01
Paste a short draft and inspect its readability and word statistics.
- 02
Compare prose, code, and non-English text in the token counter.
- 03
Reserve other input and output tokens, inspect the context limit, and copy the budget report with its assumptions.