Image compressor and resizer — shrink photos without uploading
Resize and compress several images at once. Nothing is uploaded and no account is needed.
Resize and compress multiple images in the browser. Choose JPG, PNG or WebP, download individual files or a ZIP, and keep every file on your device.
Why this runs in the browser
Most online image compressors upload your file, process it on a server and send it back. Convenient, but your file passes through someone else's machine. For a business card, a contract or a photo of your kids, that alone is a reason to hesitate. This tool redraws the image on a canvas and saves it locally, so nothing leaves your device. Load the page, then disconnect from the internet and it still works — that is the proof.
Where to put the quality slider
JPEG compression discards the information your eye is least likely to notice. So lowering quality a little changes almost nothing at first, and then past a certain point the image collapses quickly.
- 0.85 and above — for anything you will print or view enlarged. The file barely shrinks
- Around 0.7 — blog posts and document attachments. Large size reduction with little visible damage; this is the practical range
- Below 0.5 — banding appears in smooth areas like sky and skin
The same setting behaves differently depending on the picture. A detailed landscape barely shrinks; a shot with a large flat background shrinks a lot.
Choose PNG when you need transparency
Choose JPG, PNG or WebP as the output. JPEG has no transparency, so choose PNG for logos, icons and cut-out product shots. For photographs, JPG or WebP is much smaller than PNG at the same visible quality.
Why file size actually matters
A phone photo today is 3–5MB. Five of them in one blog post is over 20MB, and the page becomes noticeably slow on mobile. Google factors page speed into ranking, and visitors simply leave slow pages. Hitting an email attachment limit (commonly 25MB) is usually a few photos too. For anything that will only be viewed on a screen, 1600px wide and under 300KB is enough in most cases.
Resize before you compress
Reducing the pixel width helps far more than lowering quality does. Halve the width and you have a quarter of the pixels. Phone photos are often over 4000px wide while a blog body column is around 800px — the rest is resolution the screen throws away. Unless you are printing, resize to about 1600px first and then adjust quality. Doing it in the other order forces you to cut quality much harder, and that damage is visible.
Compression is not reversible
JPEG cannot recover what it discarded. Re-saving a file that was once written at 0.5 with a setting of 0.9 does not restore quality — it only makes the file bigger. Keep the original separately. Repeatedly opening and saving the same file degrades it a little each time (generation loss), which is why a photo that has been edited several times looks unusually muddy.
Images that should not be JPEG
- Screenshots with a lot of text — JPEG handles sharp colour edges badly, so text picks up fringing. Screenshots belong in PNG
- Anything needing a transparent background — the transparency becomes black
- Charts and diagrams with thin lines — fine lines go soft
Photographs, on the other hand, are almost always better as JPEG. The same photo saved as PNG is several times larger and looks no different.
Read next
If photos look wrong because your monitor's colour is off, compression is not the problem — check with the calibration tool first.
Frequently asked
Does my image get uploaded?
No. The image is redrawn on a canvas in your browser and saved locally, so the file never crosses the network. It works with the internet disconnected — which makes it safe for documents you would not want to upload.
Can I save the result as PNG?
Yes. Choose JPG, PNG or WebP before processing. JPG or WebP is smaller for photos; PNG is the safer choice for transparency and screenshots with text.
What quality setting should I use?
Around 0.7 works well for blog posts and attachments — large size reduction with little visible damage. Raise it to 0.85 or above for anything you will print or enlarge. Below 0.5 you start seeing banding in smooth areas like sky and skin.