Compress Images.
Keep the Quality.
Compress and convert JPG, PNG, WEBP, and AVIF images, one at a time or by the dozen. No uploads, no accounts, no waiting in line. Your images stay on your device.
Drop images here, or choose files
JPG, PNG, WEBP, AVIF, GIF, BMP, TIFF, SVG in · compress dozens at once · nothing leaves your device
How it works
- 1
Drop your images
Drag in as many JPG, PNG, WEBP, or AVIF files as you want, or pick a folder.
- 2
Pick a format and quality
Choose an output format and quality once. It applies to the whole batch.
- 3
Compress in parallel
Every image is compressed in your browser at once, using all your CPU cores.
- 4
Download everything
Grab files one at a time, or download the whole batch as a single ZIP.
Supported formats
JPG
The MozJPEG encoder, the same one Squoosh uses, for smaller files at a given quality.
PNG
Lossless recompression via OxiPNG. Same pixels, smaller file.
WEBP
A modern format that beats JPG at the same visual quality, with broad browser support.
AVIF
The smallest files available today, for when every kilobyte counts.
Why MiniFile runs entirely in your browser
Most bulk image tools ask you to upload a folder of photos to a remote server, wait for processing, then download the result, and only handle one image at a time if you're using a free tier. MiniFile takes a different approach: every resize, crop, and re-encode happens locally on your device using WebAssembly builds of the same open-source encoders behind Google's Squoosh project (MozJPEG, OxiPNG, and modern WebP/AVIF encoders). Nothing is uploaded, so there's no queue, no file size cap imposed by a backend, and nothing to worry about if the photos you're compressing are private. Drop in a folder of drone photos, product shots, or screenshots, and MiniFile processes the whole batch in the same tab, with the same privacy guarantee whether you're compressing one image or five hundred.
Read more about the project on the About page, or see the full details in the privacy policy.
MiniFile for WordPress
Already running a WordPress site? MiniFile Image Optimizer brings the same compression to your media library: every new upload gets optimized automatically, and a one-click Bulk Optimize screen handles everything already sitting in your library. JPG, PNG, WEBP, and AVIF are all supported, with optional format conversion and a built-in backup so you can always restore an original.
Frequently asked questions
Do my images get uploaded anywhere?
No. MiniFile compresses every image directly in your browser using WebAssembly. Files never leave your device, so there is no upload wait and nothing to worry about privacy-wise.
How is this different from Squoosh?
Squoosh only lets you work on one image at a time. MiniFile adds true bulk compression: drop in dozens of files, apply one setting to the whole batch, and download everything as a single ZIP.
Which formats are supported?
You can compress and convert to JPG, PNG, WEBP, or AVIF. PNG output is always lossless (via OxiPNG); JPG, WEBP, and AVIF use an adjustable quality slider.
Can I drop in a GIF, BMP, TIFF, or SVG?
Yes, all four are accepted as input and get converted to whichever output format you pick. Only static (non-animated) GIFs are supported for now, since animated output is a different feature MiniFile does not do yet.
Is there a file size or file count limit?
No hard limit is enforced by MiniFile itself. The practical ceiling is your device’s memory and CPU, the same as any other browser tab.
Is MiniFile free?
Yes. There are no accounts, no upload quotas, and no paywalled formats.
Which format should I actually pick?
For photos, WEBP usually gives the best balance of size and quality with broad browser support. AVIF compresses even smaller at the same visual quality but takes longer to encode and has slightly less universal support. JPG remains the safest default for maximum compatibility. PNG is best reserved for images that need transparency or hard edges, like logos and screenshots with text.
Why is AVIF slower than the other formats?
AVIF uses a more sophisticated compression algorithm than JPG or WEBP, which is what lets it produce smaller files at the same quality, but that extra work means it takes longer to encode, especially on large batches. If you are compressing hundreds of images and speed matters more than the last few kilobytes, WEBP is usually the better trade-off.
Does resizing lose quality?
Any downscale is a one-way operation, so keep your originals if you might need a larger version later. MiniFile uses a high-quality Lanczos resampling filter for resizing, the same class of algorithm used by professional image editors, so results stay sharp rather than blurry or aliased.