Compress Image
Shrink JPG, PNG, WebP and AVIF without guessing: set a file-size ceiling, watch the quality score you are left with, and keep or strip the EXIF.
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Pick a file in the list to see it here at full size, then drag the handle to compare before and after.
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Batch result
The ZIP keeps your file names and swaps the extension to match the encoder that won.
Why compress images here?
Compression is usually a slider you guess at. This page measures what you ended up with instead.
- A ceiling, not a slider: set 500 KB and the encoder bisects quality, then drops pixels, until the file fits.
- Proof, not promises: every result is decoded again and compared with your original for SSIM, PSNR and a single quality score.
- The same encoders a desktop tool uses — Mozjpeg, libwebp, libavif and oxipng — running in WebAssembly inside your tab.
- Your location stays home: EXIF and GPS are read on the spot so you can see what is in the file, then stripped in the same pass.
How to compress an image
Drop the files
One photo or two hundred — JPG, PNG, WebP, AVIF, GIF, BMP and SVG are read locally.
Tip: paste straight from the clipboard with Ctrl+V if the file is already open somewhere.
Choose where it goes
Pick a destination preset, or set a format and quality yourself, or give the batch a file-size ceiling to fit under.
Check, then take the ZIP
Drag the compare handle, read the score, and download one archive when the batch is done.
Frequently Asked Questions
Are these files uploaded anywhere?
No. The decoders, the four encoders and the quality measurement all run in this tab. The network is only used once, to fetch the WebAssembly encoders themselves.
Which format should I pick?
Photos: WebP or AVIF are much smaller than JPEG at the same quality, but JPEG is still the safest for email and older software. Flat artwork, logos and screenshots with text: lossless WebP or PNG through oxipng — JPEG will ring the edges of every letter. Auto picks the smallest of the formats it is allowed to use.
Why does my file get bigger?
Re-encoding an already-tight JPEG, or sending flat art through a lossy codec, both add bytes. The list marks those rows in amber and keeps the original in the ZIP when it was smaller.
What is SSIM, and what is a good score?
SSIM measures whether structure survives the compression; PSNR measures raw pixel error. Above 99 the difference is essentially invisible; 90-98 is normal for a web photo; below 85 you should be able to see blocks or banding in the comparison view.
Can I hit an exact file size?
You can set a ceiling, which the solver never exceeds. Codecs jump in discrete steps, so the result usually lands a few per cent below the number rather than on it.
Does PNG compression lose quality?
No. oxipng only re-arranges the file — filters, bit depth and metadata — the pixels are identical, which is why its SSIM reads 1.0000 and PSNR is infinite.
Why is AVIF slow on my machine?
AVIF is a heavy encoder and this page pins it to a single thread so it works on every browser. Raise encoder speed to 8-10 for batches and the time drops by most of an order.
Is there a limit on file count or size?
No account, no quota. The practical ceiling is your own memory: images above 40 megapixels are refused rather than freezing the tab.
Try It Free
No signup, no watermark, no upload — drop an image and watch the byte count fall.
Compress My Image