About next-convert
next-convert is a file converter that runs in your browser. It is built on a simple idea: converting a file should not mean handing it to someone else's server.
Why it runs in your browser
Most online converters work by uploading your file, converting it on a server and letting you download the result. That works, but your file now sits on a computer you don't control, usually with a promise that it will be deleted after a few hours.
Modern browsers can do most of this work themselves. next-convert loads the conversion code together with the page and runs it on your device. There is no upload, no queue and no copy left behind on a server.
What powers it
Your browser's image engine
Reads JPG, PNG, WEBP, AVIF, GIF and BMP, and writes JPG, PNG and WEBP.
WebAssembly
Runs compiled libraries for formats browsers don't handle natively, such as HEIC photos.
Web Audio and WebCodecs
Built-in audio and video decoders and encoders, with hardware acceleration where available.
Web workers
MP3 encoding runs in the background, so the page stays responsive.
Open-source credits
next-convert stands on the work of these open-source projects. Each is used under its own license and served from next-convert.com.
| Project | Used for | License |
|---|---|---|
| PDF.js 6.4.299 | Reading and rendering PDF files | Apache 2.0 |
| Mediabunny 1.62.1 | Reading and writing video containers | MPL 2.0 |
| heic-to 1.6.6 (libheif) | Decoding HEIC and HEIF photos | LGPL 3.0 |
| lamejs 1.2.1 (LAME) | Encoding MP3 audio | LGPL 3.0 |
| SheetJS Community Edition 0.20.3 | Reading and writing spreadsheets | Apache 2.0 |
| gifenc 1.0.3 | Encoding GIF images | MIT |
| UTIF.js 3.1.0 and pako 2.1.0 | Reading and writing TIFF images | MIT, Zlib |
| Geist and Geist Mono | Typefaces | SIL Open Font License 1.1 |
| Phosphor Icons | Interface icons | MIT |
| Photo by Alexey Topolyanskiy | Sample image in the format comparison | Unsplash License |
See it for yourself
Convert a file and watch your network tab: nothing leaves your device.