How to use this tool
- 1Add up to 30 JPG, PNG or WebP images.
- 2Pick a preset, or set the quality, output format and size.
- 3Click Compress and compare before and after.
- 4Download images one by one or all together as a ZIP.
Supported formats
- Input
- JPG, JPEG, PNG, WebP
- Output
- JPEG, PNG or WebP
Features
- MozJPEG, libwebp and OxiPNG encoders running in your browser
- Format conversion, with a background colour for transparent areas
- Optional resizing in the same step
- Before/after comparison slider
- ZIP download for batches
Compress any common image format
Add up to 30 images at once. SlimMyFile decodes each one in your browser, applies your settings and re-encodes it using professional encoders compiled to WebAssembly: MozJPEG for JPEG, libwebp for WebP and OxiPNG for PNG.
Choosing the right output format
Converting can save more than compressing alone:
- WebP — usually the smallest for photos and graphics, with transparency. Supported by all modern browsers.
- JPEG — the most compatible format for photos. No transparency.
- PNG — best for screenshots, logos and graphics with sharp edges or transparency.
Honest results
Every figure you see is calculated from the actual bytes of the output file. If a result is larger than your original, we say so — and when nothing changed except the size, we simply keep your original.
Your privacy
Files are read and processed by your browser on this device. They are not uploaded, stored or shared, and closing the page discards them. Processing speed and the largest file you can handle depend on your device.
Frequently asked questions
How many images can I compress at once?
Up to 30 images per batch. Images are processed one after another to keep memory use under control, and you can download them individually or as a ZIP.
Will compression remove my photo’s location data?
Usually yes. Re-encoding creates a new file without the original EXIF metadata, including GPS location and camera details. Orientation is applied to the pixels first so photos stay upright.