How to use this image compressor
Most images published on the web are two to five times larger than they need to be. A phone camera writes a JPEG at maximum quality with full EXIF metadata attached, and that file goes straight into a blog post, a product listing or an email attachment without anyone re-encoding it. This page re-encodes it for you, and it does so entirely inside the browser tab you already have open.
Start by dropping your images onto the box above, or tapping it to open the file picker. You can
add as many images as you like; they are queued and processed one after another so a batch of
twenty photos does not lock up your phone. Each file stays in memory as a File object —
the browser never sends it anywhere.
Choosing a quality level
The quality slider maps directly to the encoder quality parameter passed to
canvas.toBlob(). It is not a linear scale and it does not mean "75% of the original
detail". In practice, photographs with a lot of texture — foliage, fabric, crowds — hold up well
down to about 65. Images with large flat areas and hard edges — screenshots, logos, diagrams,
charts — start showing ringing artefacts around the edges much earlier, so keep those above 85 or
use PNG instead.
A good working method is to compress once at 75, download the result, and compare it side by side with the original at 100% zoom. If you cannot see a difference, drop to 65 and check again. Stop at the first setting where you can see the difference and go one step back up.
Which output format to pick
WebP is the default here because it is now supported by every current browser and typically produces files 25–35% smaller than JPEG at matching visual quality. It also supports transparency, so it can replace both JPEG and PNG in most web contexts. Pick it unless you are handing the file to a system that specifically demands JPEG.
JPEG remains the safest choice for anything that will be opened by older software, printed, or uploaded to a platform with strict format rules. Note that JPEG has no transparency: if your source image has a transparent background, this tool fills it with white rather than producing a black rectangle, which is what a naive canvas export would give you.
PNG is lossless, so the quality slider is disabled when you select it. PNG will rarely make a photograph smaller — it may well make it larger. It is the right choice for screenshots, line art, icons and anything with sharp text, where JPEG-style artefacts are unacceptable.
The setting that actually matters: dimensions
Compression quality gets all the attention, but resizing usually saves far more. A 4032 × 3024 photo from a phone contains roughly 12 million pixels. Displayed in a blog post at 800 pixels wide, 95% of those pixels are thrown away by the browser after they have already been downloaded. Setting the "cap the longest side" field to 1600 or 1920 before compressing routinely turns a 4 MB photo into a 180 KB one — a result no quality slider alone will reach.
Use 1920 for full-width hero images, 1200 for in-article images, and 600 for thumbnails and avatars. If you are preparing images for a retina display, double those numbers and let the browser scale them down.
What happens to metadata
Because the image is redrawn onto a canvas and re-encoded from raw pixels, all EXIF data is discarded: camera model, lens, timestamp, and — importantly — GPS coordinates. That is a privacy win if you are publishing photos taken at home, and something to be aware of if you rely on EXIF for cataloguing. Keep your originals; treat the compressed copies as publishing artefacts.
One consequence worth knowing: some images rely on the EXIF orientation flag to display the right way up. Modern browsers apply that flag when decoding, so the compressed output will be correctly oriented in almost every case. If you hit an old file that comes out rotated, open it once in any image viewer, re-save it, and run it through again.
Working with large batches
The "Download all" button triggers the downloads in sequence with a short delay between each one, because browsers block rapid-fire download calls as a popup-protection measure. If your browser still asks permission to download multiple files, allow it once and the rest will follow. For very large batches — more than about fifty files — process them in groups so you can keep track of which ones succeeded.