About Convertly Tools

What this is

Convertly Tools is a collection of 29 free online utilities for converting, compressing, and resizing images, working with PDFs, and, for developers, tidying JSON and drafting skill files for Claude. There’s no signup, no watermarks, and no artificial limits. Pick a tool, drop a file, download the result. Alongside the tools are 27 plain-English guides to the formats and questions behind them.

Who builds it

Convertly Tools is built, tested, and written by Rehan Shah, a designer and developer who started it in August 2026 as a personal project after one too many converter sites asked for an upload, an account, or a subscription to do a thirty-second job. Every tool, every guide, and every line of the site’s code is the work of that one person; there is no content team and no outsourced writing. The code is on GitHub.

The site launched with fifteen tools and has grown to 29. It is free to use, supported by unobtrusive advertising, and your files, which we never receive, are not part of the deal.

How tools are tested

A tool is not listed until it works. The site has a rule in its own code that a tool appears in the directory and the sitemap only when both its implementation and its landing page exist, so there are no placeholder pages promising a feature that is coming.

• Every tool is run on real files in a desktop browser at full width and on a phone before it ships, and again after any change to it.
• The numbers in the guides are measured, not quoted: when a guide says a text-only PDF grew from 74.7 KB to 1.9 MB under image compression, that is the result of running the file through the tool and reading the size.
• Claims about formats and software are checked against the primary source, and the Claude Skills guides list those sources at the end of each page with the date they were checked.
• Privacy claims are written per tool. The one tool that sends text to an outside service, the SKILL.md Generator, says so on its page and in the privacy policy.

That is not the same as being infallible. Browsers change, formats have odd variants, and a scan or a screenshot can trip a decoder in a way the test files did not. When that happens, the fix goes out as soon as it is understood, and the guide or page is corrected rather than left standing.

Why it exists

Everyday file jobs are small problems: an iPhone photo that won’t open on Windows, a PDF just over an upload limit, a batch of screenshots that should be one document. Most converter sites solve them by making you upload your files to their servers and wade through popups to get them back. That trade never sat right with us. Modern browsers are powerful enough to do this work themselves, so we built tools that do.

How it works

Every file tool on this site runs in your browser using modern web technology: the Canvas API, WebAssembly, and in-browser PDF libraries. Your files are processed on your own device and are not uploaded to a server. The one exception, the SKILL.md Generator, sends the description you type to Anthropic’s API and says so on its page. That makes conversions faster (no upload/download round trip) and keeps your documents and photos private. We explain the machinery, and how to verify the claim yourself, on How in-browser processing works.

Found a mistake?

Bug reports, corrections to a guide, and tool requests all reach a person, and the reply comes from the same one who wrote the code. Get in touch. For a bug, the three things that make it fixable are the browser you used, the file type and size, and what you expected to happen. Do not attach anything confidential; a description is enough, and a file that fails can usually be reproduced from one that is similar.

What’s next

The toolbox grows based on what people actually need. Recent additions came from exactly that: BMP, GIF, AVIF and TIFF conversion, text extraction from PDFs, cropping and rotation, on-device AI photo tools, and the first developer tools. If something you need is missing, tell us.