About Ketchio Tools

Ketchio Tools is a set of 14 file utilities maintained by one independent developer. Most tools process files entirely in your browser; Translate an EPUB sends book text directly to a provider you choose.

Why this exists

Most free online file tools work the same way: you upload your document, a server somewhere processes it, and you download the result. That is a reasonable design for heavy work, but it is a poor bargain for the everyday tasks people actually need — splitting a payslip, rotating a scanned form, checking a subtitle file. Those are small jobs, and the browser on your desk is already fast enough to do them. Sending a private document to a stranger’s server to have four pages deleted from it is a cost with no matching benefit.

That is why the PDF, subtitle, lyrics and validation tools do their work locally. Your file is read from your disk into the browser tab and processed there, without a Ketchio file-upload endpoint. The EPUB translator is clearly marked because translation requires sending the book text to the model provider selected by the user.

How the tools are built

The site is static HTML generated with Astro, served from a CDN, with a small JavaScript bundle per tool. PDF work uses pdf-lib for document manipulation and Mozilla’s pdf.js for rendering. Subtitle, lyrics and EPUB parsing is written from scratch in TypeScript, with unit tests covering the parsing and transformation rules. There are no external web fonts, advertising pixels or cookies. The hosting platform injects cookie-free Cloudflare Web Analytics, which is described in the privacy policy.

Every tool page states what that tool cannot do, alongside what it can. Rasterising compression destroys the text layer. Merging drops the bookmark tree. Image extraction cannot see vector artwork. These are real limits of the approach, and hiding them would only waste the time of whoever discovers them the hard way.

What this site is not

It is not a company, and there is no account system, no paid tier and nothing to sign up for. It is not a replacement for professional tooling: the EPUB validator is a structural check rather than EPUBCheck, and the subtitle rules follow published broadcast guidelines rather than any particular client’s house style. If a tool here gets you to a good enough answer in ten seconds, it has done its job.

Also by the same developer

JpMaster is a free JLPT study site: vocabulary and grammar drilled with spaced repetition, and typing practice that checks the kana rather than the romaji you typed to get there. It shares nothing with this site but the person maintaining it and the domain it sits under.

Contact

Bug reports, broken files that should work, and requests for tools are all welcome at[email protected]. Please describe what you dropped, what you expected and what happened instead — and do not attach the file itself unless you are comfortable sharing it, since a description is usually enough to reproduce the problem.