About JFIF.IO
Last updated September 26, 2026
JFIF.IO is a free toolkit for everyday image work: converting between formats, compressing, resizing, cropping, inspecting metadata and creating favicons. It started with a simple frustration — images saved as .jfif that nothing would accept — and grew into a complete set of image utilities.
How it works
Most online converters upload your files to a server, process them there and send them back. JFIF.IO does the work on your own device instead:
- Your browser’s built-in image engine decodes and encodes common formats such as JPG, PNG and WebP.
- WebAssembly builds of established open-source encoders — libavif, libwebp, MozJPEG and OxiPNG — handle AVIF, advanced compression and lossless optimisation.
- Formats browsers cannot read on their own, such as TIFF, HEIC and PDF, are decoded with open-source JavaScript and WebAssembly libraries.
- The heavy lifting runs in background workers, so the page stays responsive even with large batches.
Because the files never leave your device, conversion is fast — there is no upload queue — and private by design.
When a server is involved
If your browser cannot decode a particular file, the converter may offer to process it on our server instead. This only happens after you click to allow it for that file. The file is sent over an encrypted connection, converted in memory and returned immediately; it is not written to disk or stored.
What we believe
- Useful for free. The core tools require no account, add no watermarks and have no artificial daily limits.
- Honest numbers. File sizes, savings and dimensions you see are measured from the actual files.
- Accurate information. Our format guides explain what each format really does, including its limitations.
- Respect for attention. If we show advertising, it is clearly labelled, never placed inside the tools, and only shown with your consent where consent is required.
Contact
Questions, ideas or a bug report? Use the contact form — we read every message.