Compression controls that stay predictable
- Keep the same input format or choose JPG, WebP, or PNG.
- Choose Original to keep pixel dimensions unchanged.
- PNG stays lossless here; reduce dimensions or choose JPG/WebP for stronger size reduction.
Free Image Compressor
Compress JPG, JPEG, PNG, and WebP images to reduce file size locally in your browser with no upload.
Runs on your device — no upload required
Drop or choose imagesChoose files from your device or drag them hereYou can also paste an image with Ctrl+V / Cmd+V.
Compress photos and reduce image size without an upload. This JPG, JPEG, PNG, and WebP compressor preserves aspect ratio and only reduces dimensions when you choose a smaller maximum.
How OpenFileTools processes it
Local processing, explicit choices.
The browser decodes the image, calculates an aspect-ratio-safe output size, encodes the selected format locally, and reports original bytes, output bytes, dimensions, format, and measured savings.
Quick technical summary
What this tool changes.
| Property | Behavior |
|---|---|
| Processing | Browser only; no image upload |
| Original | Never changed |
| Output | Same as input, JPG, WebP, or PNG |
| Dimensions | Original or proportional maximum |
Compression is not the same as resizing
Quality controls how aggressively the browser encodes JPG or WebP; maximum dimension controls whether oversized pixel dimensions are reduced. Choose Original dimensions when only encoding should change.
- Same as input is the default output format.
- PNG is lossless in this browser flow, so the quality slider does not apply.
- Aspect ratio remains unchanged and no fixed saving is promised.
Read the measured result
An already optimized image can become larger after re-encoding. OpenFileTools reports dimensions, format, original bytes, processed bytes, and percentage saved only after the browser has created the output.
- Keep the original when the processed result is larger.
- Lower quality gradually and inspect visible detail.
Questions, answered.
Will compression resize my image?
Only when you choose a maximum dimension smaller than the source.
Why did my file become larger?
The source may already be efficiently encoded for its content.
Can you promise a percentage reduction?
No. Savings depend on source detail, format, dimensions, and quality.
When should I keep original dimensions?
Use Original when pixel size must not change and you only want to test a new encoding.