Image, PDF, calculators, converters, text and developer tools — fast, free, and running right in your browser so your files never leave your device.
Try a different word — like “convert”, “calculator” or “password”.
Grabnix is a collection of 60 single-purpose web tools for the small tasks that come up constantly and never justify installing software: working out a loan instalment, getting a photo under a portal's size limit, merging three PDFs before a deadline, or checking how many days remain until a due date.
There is no account to create, no email address to hand over, and no result hidden behind a sign-up. Open the tool, get the answer, close the tab.
Nearly every tool here runs entirely in your browser. The image compressor and converters use the Canvas API to decode and re-encode locally; the PDF tools use a library loaded into the page; the calculators are plain arithmetic on the values in the input boxes. Nothing is uploaded, queued on a server, or written to a database.
You can confirm that yourself: open your browser's developer tools, switch to the Network tab, and use any tool. You will see the page load, and no request carrying your file or your input. The single exception is converting Office documents to PDF, which needs a rendering engine that cannot run in a browser — that one is documented in full, including exactly when the upload is deleted, in our privacy policy.
Underneath every calculator is the formula it uses, with each variable defined, so you can check the arithmetic rather than trust it. Every page carries at least one fully worked example with real numbers, a reference table where one is useful, and an honest account of the tool's limits — which conventions it follows, where those conventions stop applying, and when the tool is the wrong instrument entirely.
Health calculators state plainly that they produce population estimates rather than diagnoses. Financial calculators state what they exclude, such as fees, taxes and insurance. We would rather send you to a professional than have you act on a number this site was not built to produce.
Use the search box above to jump straight to what you need, or browse by category. If a tool you want is missing, or one of ours gives you an answer you can show is wrong, tell us — several tools here exist because somebody wrote in.