About OneConvert
What is OneConvert?
OneConvert is a collection of free browser-based tools for everyday file conversion and transformation tasks. It covers PDF editing (split, merge, compress, rotate, watermark, page numbers, grayscale), image conversion (JPG, PNG, WebP, HEIC, SVG, favicons, crop and resize), QR code generation and reading (WiFi, vCard, email, plus a decoder), unit conversion (length, weight, temperature, data storage, CSS units and number bases), fourteen text tools, colour tools for conversion, WCAG contrast, palettes and gradients, and a set of everyday calculators — sixty-one tools across seven categories.
Every tool runs entirely in your browser. There is no server that receives your files, no backend that processes them, and no cloud storage involved. Files are read into your browser's memory, processed using JavaScript libraries, and the result downloads directly to your device.
Why browser-based?
The traditional model for online converter tools involves uploading your file to a server, waiting for it to be processed remotely, and then downloading the result. This introduces privacy concerns — you are trusting the tool provider with your document content — as well as performance bottlenecks from network transfer, and dependency on a server infrastructure that may have limits or downtime.
Modern browsers are powerful enough to handle these operations locally. pdf-lib and pdf.js from Mozilla handle PDF operations. The Canvas API handles image conversion at full quality. JavaScript BigInt handles arbitrary-precision number conversion. The result is a tool that is faster than a server-based equivalent for most operations, works offline once loaded, and is completely private by design.
No limits, no account
Most free online converters are gateways to paid subscriptions. They offer a limited number of operations per day, cap file sizes, or reserve useful features for paying users. OneConvert has no such restrictions. There is no account to create and no subscription model. All sixty-one tools are fully functional with no usage limits — the only constraint is your device's available memory.
The service is funded by non-intrusive advertising through Google AdSense. Ads are clearly labelled and placed in ways that do not interfere with tool functionality.
The tools
PDF tools — Split pages into a new document, merge multiple PDFs, compress by stripping metadata, rotate specific pages, reorder by drag-and-drop, delete page ranges, add text watermarks (CONFIDENTIAL, DRAFT, custom), add page numbers in multiple formats, convert to greyscale, convert images to PDF, export pages as PNG images, and convert text-based PDFs to editable Word documents.
Image tools — Convert between JPG, PNG and WebP in both directions, convert iPhone HEIC photos to universally compatible JPG, and rasterise SVG vectors to PNG at any resolution. Crop to any size or aspect ratio, rotate in 90-degree steps or mirror, resize to exact pixel dimensions with aspect ratio lock, and compress with a live quality preview. A favicon generator produces every icon size browsers and devices ask for, and an encoder turns a small image into a Base64 data URI for inlining in CSS or HTML.
Developer tools — CSS unit converter (px to rem, em, vh, vw, pt, with separate root and parent font sizes so em is calculated correctly), number base converter (binary, decimal, hexadecimal, octal with bit breakdown), and Unix timestamp converter (epoch to date and back, with relative time). Alongside those: a JSON formatter and validator that reports the failing line, a hash generator for SHA-256, SHA-1 and SHA-512 via the Web Crypto API, a version 4 UUID generator, a password generator using the browser's cryptographic random source, a CSV to JSON converter that handles quoted fields and embedded newlines, and a CSS gradient generator with a live preview.
Other tools — QR code generator (URL, WiFi, text, email, phone — PNG and SVG export), unit converter (length, weight, temperature, speed, area, volume, data), text tools (word count, case converter, Lorem Ipsum, Base64, remove duplicates, URL encode), and colour tools (HEX/RGB/HSL converter, WCAG contrast checker, palette generator).
Privacy
File content is never transmitted to any server. Locally stored data is limited to your cookie consent choice and theme preference (dark/light mode). Google Analytics collects anonymised usage statistics only with your consent. Full details are in the Privacy Policy.
Contact
Questions, feedback or privacy requests: [email protected]