The workshop · Compress an image
How it works : Compress an image
Drop an image in, or a whole batch. Pick a width, pick a quality, walk away with lighter files. The originals are untouched, and they never leave your device.
A phone photo today weighs somewhere between three and twelve megabytes. That is too much for an email attachment, too much for a government form capped at two megabytes, and far too much for a picture that will end up displayed a thousand pixels wide. Shrinking it is the most ordinary job on the web, and it is also the one with the most sites asking you to hand over your file.
Here the files stay with you, whether you drop in one or thirty. Each image enters a queue on screen, gets redrawn at the size you asked for, saved again at the quality you asked for, and its own line says where it stands: waiting, in progress, done, or refused with the reason. Both weights are shown file by file, never as a convenient average.
One useful consequence of that re-save: it copies NONE of the original metadata. The date, the camera and the coordinates of where you were standing are simply not in the compressed files. The tool tells you exactly what the browser wrote in their place.
How it works
- Drop one or several images on the drop zone, or choose them, or paste a screenshot from the clipboard.
- Pick a maximum width and a quality, applied to the whole batch. Width is what makes the biggest difference: halving the width quarters the number of pixels.
- Click the compress button. The images are processed one after another, each line of the queue shows its two weights and its saving, and the files download.
Formats accepted
These three families are the ones EVERY browser can both open and re-save, with one named reservation for WebP on Safari. The compatibility matrix says exactly where the limits are, browser by browser.
JPEG photo (.jpg, .jpeg)
The commonest case, and the one where compression pays most: the quality dial really does move the weight. Output is JPEG.
PNG image (.png)
A PNG has no quality setting: it is lossless by design. The only real lever is size. For a PHOTO saved as PNG, the tool offers to re-save it as JPEG, which changes everything, and it says so instead of doing it behind your back.
WebP image (.webp)
Output is WebP wherever the browser can write it. On Safari no version can write a WebP: the tool detects that, produces a JPEG and says so on screen rather than handing you a file that is not the one you asked for.
Its limits
50 MB per file
Beyond that, a phone short of memory crashes the tab instead of returning a result. The limit is a piece of honesty, not a commercial leash.
About 16.7 million pixels per image
On iPhone and iPad, canvas area was capped at 4096 by 4096 pixels for years, and allocation fails beyond it: the tab dies instead of producing anything. The tool checks the area BEFORE allocating and refuses cleanly, saying why. In a batch, only the offending image is refused: its line says so, the others carry on.
Several downloads at once
When a batch produces several files, your browser may ask permission for multiple downloads: it is the browser protecting your downloads folder, and we do not work around it. Every line in the queue keeps its own button to fetch a file again if needed.
The result is always re-encoded, never copied
The browser redraws the image: that is a fresh compression, even at quality 100. A file that was already heavily compressed can therefore come out HEAVIER, and the tool tells you so instead of selling you a saving that does not exist.
Animated images lose their animation
A canvas holds one still frame: an animated PNG or WebP would come out as its first frame only. The tool detects that and refuses, rather than handing back a maimed file without warning.
Questions about this tool
Is my image sent anywhere?
No, and you do not have to take our word for it. Open your browser's inspector with F12, go to the “Network” tab, clear the list, then drop your image in. Not one line appears. You can also cut your connection: the tool keeps working.
Which quality should I pick?
For a photograph headed for a screen or an email attachment, 80 is an excellent compromise: the difference is invisible to the naked eye and the weight often halves. For an illustration on a website, 75 does the job. Below 60, large flat areas and skies start to band. Above 92, the weight climbs fast without the eye gaining anything.
Why does my PNG barely get smaller?
Because PNG is a LOSSLESS format: it has no quality setting, it records every pixel exactly. On a drawing, a logo or a screenshot, that is precisely what you want. On a photograph it is the wrong format, and the only real lever is size. The tool then offers to re-save the photograph as JPEG, and it leaves the choice to you.
The file I got is heavier than the original. Why?
Because the browser does not copy your file: it redraws the image and encodes it afresh. If your original had already been squeezed as far as it goes by another tool, or if it is a flat-coloured drawing pushed through JPEG, the result can weigh more. The tool says so plainly rather than showing a negative saving in small print, and the right move is to keep your original.
Does compressing strip the GPS data from my photo?
Yes, and that is a useful side effect: re-encoding an image copies none of the original metadata. The date, the camera model and the coordinates disappear. The browser does write two blocks of its own into a JPEG it builds, a format label and a colour profile, and neither says anything about you. If you want a file with not a single block left, run it through the metadata tool afterwards: that is its trade, and it will show you there is nothing left.
Can I process several images at once?
Yes. Drop them in together, or select several in the file picker: each image enters a queue on screen, with a line of its own. The settings apply to the whole batch, the images are processed one after another to spare the device's memory, and each line shows its two weights, its saving, and its own download button. If one file in the batch is refused, its line says why, and the others carry on. Your browser may ask once for permission to download several files: that is its normal protection.
What about AVIF, HEIC or TIFF files?
They are not in the list of accepted formats, and that is deliberate. AVIF opens everywhere but can only be re-saved on recent Chrome; the HEIC from iPhones only opens on Safari; TIFF only displays on Safari. A tool that announced them would be lying to a good share of its visitors. The compatibility matrix shows the detail, browser by browser.
Drop an image in, or a whole batch. Pick a width, pick a quality, walk away with lighter files. The originals are untouched, and they never leave your device.
VerifyThe proof, step by stepThe network inspector check, explained one gesture at a time, with screenshots.
The cornerThe image cornerA photo says more than it shows. Here you see it, clean it, slim it down, crop it, and blur what is nobody's business.