Free · In your browser · No upload
Compress images in bulk
Shrink a whole folder of images at once and see the size saved on every file.
Settings
75–85% is usually indistinguishable from the original.
Just one image? Use compress an image.
Need more than one operation? Open the full editor to combine tools and reorder your edits.
Compressing a batch is mostly a question of picking one quality level that suits every image in it. Our measurements showed the same setting producing very different file sizes depending on content — a smooth landscape and a densely textured photograph compress quite differently at quality 80 — so the per-file before and after sizes shown here matter more than the number on the slider.
The quality curve is worth knowing before you choose. Between roughly 75 and 85 you get small files with artefacts that are hard to spot; above 90 the file grows steeply for changes almost nobody can see. We measured quality 100 costing dramatically more than 90 across every test image while delivering nothing useful.
How it works
- 1
Drop your images onto the workspace.
- 2
Pick WebP for the smallest results, or JPEG for maximum compatibility, and set a quality — 75 to 85 suits most photographs.
- 3
Click Process all, then review the before and after size on each row to check the setting suits the batch.
- 4
If the savings are not enough, resizing the images first is a bigger lever than lowering quality further.
Frequently asked questions
How much space will I actually save?
It varies more by image than by setting. Smooth photographs compress dramatically; densely textured ones far less, because there is less redundancy to remove. Each row shows the exact before and after size, so you can judge the whole batch before downloading any of it.
What quality should I choose for a mixed folder?
Start at 80. It sits on the flat part of the quality curve, where files are small and artefacts are hard to see, and it behaves sensibly across different kinds of image. Drop to 65–70 if the images are only ever displayed small, such as thumbnails.
Is there a file size or count limit?
No hard limit — everything runs on your device, so there is no server quota to hit. Files are processed a few at a time to keep the browser responsive, and very large images simply take longer per file.
Will compressing already-compressed images help?
It will make them smaller, but each lossy encode compounds the damage from the previous one. If you still have the originals, compress from those instead — re-compressing a folder of already-optimised JPEGs is where visible quality loss usually creeps in.
Can I compress to PNG for a lossless batch?
PNG has no quality setting to adjust, so it is not offered here. For a lossless batch, use bulk convert with PNG as the output format; for genuinely smaller files, WebP is the better answer since it also preserves transparency.