One place for all your
converter tools
PDF, images, QR codes, units, text and colors — convert anything instantly. Everything runs in your browser. Your files never leave your device.
PDF Tools
Split, merge, compress, rotate, reorder, delete pages, convert images to PDF and more.
Image Tools
Convert between JPG, PNG, WebP and HEIC. Crop, rotate, resize and compress images.
QR Code Tools
Generate codes for URLs, WiFi, contacts, email and phone — or read one back from an image.
Unit Converter
Length, weight, temperature and data storage, plus CSS units, number bases and timestamps.
Text Tools
Word counter, case converter, Lorem Ipsum, Base64, diff checker, regex tester, JSON and CSV.
Color Tools
Convert HEX, RGB and HSL, check WCAG contrast, build palettes and write CSS gradients.
Calculators
Percentages, exact age, the days between two dates and unbiased random numbers.
Most used tools
The conversions people reach for most often — each opens directly, with no upload and no account.
100% Private
Files stay on your device
Instant
No server processing
Always Free
No subscriptions ever
No Account
Open and use immediately
Any Device
Desktop, tablet, mobile
100% Private — Files Never Leave Your Device
Unlike most online converter tools, OneConvert processes everything locally in your browser using JavaScript. Your files are never uploaded to any server. What you work with stays with you — completely private by design.
Complete PDF Toolkit — Free Online
Split PDFs into individual pages, merge multiple files, compress for email, rotate pages, reorder, delete and convert between formats. All twelve PDF tools run instantly in your browser with no file size limits and no registration required.
Image Converter Supporting All Major Formats
Convert JPG to PNG, PNG to WebP, HEIC to JPG and more — instantly. Compress images to reduce file size, resize by pixel or percentage, and batch process multiple files at once. iPhone HEIC photos are converted on-the-fly.
Unit Converter for Length · Weight · CSS Units · Binary/Hex & More
Convert between metric and imperial units instantly. Length, weight, temperature, speed, area, volume and data storage — all in one clean interface with a full reference table showing all values simultaneously.
Why OneConvert is different
🔒 Your files never leave your device
Most online converter tools upload your files to a server, process them remotely, and then delete them — they say. OneConvert works differently: every single operation runs directly in your browser using JavaScript. When you select a PDF to split, it is read into your browser's memory. When you convert an image, the Canvas API handles it locally. No data is transmitted. Your files stay on your device from start to finish.
⚡ No account, no limits, always free
Many popular converter tools are free up to a point — then hit you with daily limits, file size caps, or a paywall for basic features. OneConvert has none of those. There is no account to create, no subscription tier, no limit on how many files you can process or how large they are. The only constraint is your browser's available memory, which on a modern device is several gigabytes.
🛠️ Built for everyday use
OneConvert covers the conversions and edits that come up regularly — splitting a PDF to share one section, compressing an image before uploading it, generating a QR code for a link, converting between CSS units while building a website, or checking whether two colours have sufficient contrast for accessibility. Sixty-one tools across seven categories, each with its own URL and focused functionality.
🌐 Works on any device
Because everything runs in the browser, OneConvert works on Windows, macOS, Linux, iOS and Android without installing anything. The interface adapts to any screen size. PDF processing uses pdf-lib and pdf.js. Image conversion uses the Canvas API. QR generation uses qrcode.js. These are well-tested, widely used JavaScript libraries — not experimental code.