How much smaller will my image get?

It depends entirely on the picture and the quality you pick, so this page reports the real numbers instead of promising a figure. Photographs usually shrink a lot with WebP or AVIF at quality 0.7–0.8, because they throw away detail the eye barely notices. A screenshot saved as PNG may barely change, and a re-encoded JPEG can even grow if it was already optimised.

Why does the quality slider do nothing when the format is PNG?

PNG is a lossless format and has no quality parameter, so the browser ignores the value. To control file size, choose JPEG, WebP or AVIF. PNG is still the right answer when you need exact pixels or transparency.

Does compressing keep my EXIF data or the camera’s rotation?

No. The canvas re-encodes the visible pixels only, so metadata such as camera model, GPS position and the original capture time is dropped. Your browser applies the EXIF orientation tag while decoding, so the output stays upright, but it carries no metadata of its own.

How do I compress an image without uploading it?

Set a quality level and the tool re-encodes the picture in your browser, showing the before and after file size so you can judge the trade-off yourself. Nothing is uploaded, and there is no file size limit other than your device’s memory.

Runs entirely in your browser · no upload · no account · no watermark

Choose a JPEG, PNG or WebP image.
Pick the output format and drag the quality slider.
Compress, check the size it saved, then download.

Image

JPEG, PNG or WebP. The file is read by this page and never sent anywhere.

Output format

Quality 0.75

Maximum width (optional)

Leave blank to keep the original dimensions. A wider image is scaled down proportionally.

What this page can do

Quality slider from 0.1 to 1.0
Shows the original and compressed size side by side
Optional maximum width, with proportional scaling
Files are never uploaded

When to use this page

An upload form has a file-size limit and a small quality loss is acceptable.
Shrinking images before putting them on a web page.
You want to see the before/after size immediately and decide whether to keep the result.

When to use something else

You need lossless optimisation, or exact control of a target byte size — this tool takes a quality setting, not a size target.
EXIF orientation, ICC profiles, metadata or alpha semantics must be preserved.
The source is a PNG with few colours; re-encoding through Canvas can make it larger.

How it compares with other options

Dedicated encoders such as mozjpeg, oxipng or Squoosh can do lossless optimisation, progressive JPEG, palette reduction and much better size/quality trade-offs. The browser’s Canvas encoder offers none of those knobs, and PNG here is re-encoded rather than truly optimised — which is why the page shows both sizes instead of promising a reduction. If it comes out bigger, keep the original or use a dedicated encoder.

Where your files go

Nowhere. This page loads the code that does the work, and from then on the file you open is read by your own browser. There is no upload step, no temporary server copy and no cleanup to trust — the data never crosses the network, so there is nothing to delete afterwards. You can confirm it yourself: open your browser’s network panel while the tool runs and watch it stay quiet.

Questions about this tool

How much smaller will my image get?: It depends entirely on the picture and the quality you pick, so this page reports the real numbers instead of promising a figure. Photographs usually shrink a lot with WebP or AVIF at quality 0.7–0.8, because they throw away detail the eye barely notices. A screenshot saved as PNG may barely change, and a re-encoded JPEG can even grow if it was already optimised.
Why does the quality slider do nothing when the format is PNG?: PNG is a lossless format and has no quality parameter, so the browser ignores the value. To control file size, choose JPEG, WebP or AVIF. PNG is still the right answer when you need exact pixels or transparency.
Does compressing keep my EXIF data or the camera’s rotation?: No. The canvas re-encodes the visible pixels only, so metadata such as camera model, GPS position and the original capture time is dropped. Your browser applies the EXIF orientation tag while decoding, so the output stays upright, but it carries no metadata of its own.