About is.tools

What this is

is.tools is a collection of small tools for everyday file and text jobs: compressing and converting images, merging, splitting and signing PDFs, converting iPhone HEIC photos, removing a background from a photo, reading text out of a screenshot, formatting JSON, generating passwords, converting between Simplified and Traditional Chinese. The set keeps growing, and every tool is available in every language the site supports.

Every tool runs inside your browser. When you drop a file in, it is decoded, processed and re-encoded on your own machine by WebAssembly builds of the same open-source libraries the desktop programs use — MozJPEG, libwebp, libavif, OxiPNG, pdf-lib, PDF.js, libheif, QPDF, Tesseract, ONNX Runtime, OpenCC. Nothing is uploaded, so there is no queue, no size limit, no watermark and no account. Once a page has loaded it keeps working with the network off.

Who we are

A small team of engineers with backgrounds in cross-platform and network software. We are building is.tools to be the one place people anywhere go for everyday file and text jobs: the same tools, the same quality, in every major language, with nothing uploaded. There is no support desk, but there is a person who reads every message sent through the contact page and fixes things when they break, usually within a few days.

The tools are free and unlimited; the site is supported by the ads on the page. We do not sell anything, collect e-mail addresses or run affiliate links. The privacy policy says exactly what is measured and by whom.

How we decide what to build

A tool gets built only when it can be done properly in a browser, when keeping the file on your device is a real advantage rather than a slogan, and when it fits with the tools already here so results can be handed from one to the next without re-selecting files. That rules out a lot of popular things: unit converters and calculators that the search engine already answers, anything that needs a server such as Word to PDF, and anything that downloads other people's videos.

Each tool is meant to match the best desktop equivalent, not merely to work. When the browser's own encoder produced worse JPEGs than Photoshop, we replaced it with MozJPEG; when a PDF came out larger after compression, the tool learned to keep the original. If you find a case where a tool does a poor job, tell me — that is how most of the improvements here started.

Known issues

Background removal needs about 200 MB of free memory and WebGPU for the fast path; on phones with 4 GB of RAM and on browsers without WebGPU it falls back to the CPU and takes 15–25 seconds per photo, and on some older phones the model does not load at all. Image to text (OCR) reads printed text only; handwriting comes out as noise, and that is a limit of the engine, not a bug we can fix. HEIC conversion in Safari is roughly twice as slow as in Chrome because Safari's WebAssembly build of libheif runs single-threaded. PDF tools cannot open documents that are digitally signed with certificate-based signatures without breaking the signature — that is by design of PDF, not something we can work around. Translations in Japanese, Spanish, Portuguese, German, French and Russian were drafted with machine help and checked by us, not by native speakers; if a phrase reads oddly, send it to us and we will fix it.

The changelog records what we have been working on and when each change went live.