Processed entirely on your device — nothing is uploaded
How to use the image compressor
- 1Drop your images into the box above.
- 2Choose fixed-quality mode, or target-size mode if you have a hard limit to meet.
- 3Pick an output format — WebP usually produces the smallest result.
- 4Download the compressed files and check the saving reported for each.
Target size mode, and why it exists
Plenty of systems impose a hard cap: an application portal that rejects photos over 200 KB, an email gateway with an attachment limit, a marketplace listing with a per-image ceiling. Meeting those limits by guessing at a quality slider is tedious — you export, check, adjust, and repeat.
Target mode automates that loop. It performs a binary search over the quality range, encoding the image at successively refined settings and keeping the largest result that still fits under your limit. Eight passes narrow the range to within about one quality point, and because it all happens in memory it takes well under a second per image.
If even the lowest quality cannot reach your target, the tool returns the smallest it managed. When that happens the image is almost always too large in pixel dimensions rather than too lightly compressed — resize it first and then compress.
Resolution beats quality for saving bytes
This is the single most useful thing to understand about image weight. File size scales roughly with pixel count, and pixel count scales with the square of the dimensions. Halving an image's width quarters its area, and typically quarters its file size — a far bigger effect than anything the quality slider will do without visible damage.
A 12-megapixel phone photo displayed in a 600-pixel-wide column on a web page contains about twenty times more detail than anyone will ever see. Compressing it hard to fit a budget produces a soft, artefact-ridden image; resizing it to 1200 pixels wide and compressing lightly produces a crisp one at a similar size.
So the order of operations matters: resize first, compress second. The image resizer on this site is the right tool for the first step.
What each format does under compression
JPEG is the old reliable. It compresses photographs well and is accepted everywhere, but it has no transparency and its artefacts around sharp edges are distinctive and ugly.
WebP typically produces files 25–35% smaller than JPEG at matched visual quality, and it keeps transparency. For anything destined for a website, it is usually the right answer.
PNG is a poor target for compression, because it is lossless — the only way to make a PNG smaller is to reduce its dimensions or its colour depth. This is why the default here converts PNG input to JPEG output: a screenshot saved as PNG will often shrink by 90% as a JPEG, at some cost to text crispness.
One rule that applies to all of them: never compress an already-compressed image repeatedly. Each cycle compounds the previous cycle's artefacts, and the degradation is permanent.
Judging the result
The percentage saved is reported for every file, but the number to trust is your own eye. View the result at the size it will actually be seen. An image that looks poor at 400% zoom may be flawless in a web page, and one that looks fine in a thumbnail may fall apart on a retina display.
Pay particular attention to smooth gradients — skies, studio backdrops, skin. These are where lossy compression fails first and most visibly, showing banding and blotching before anything else in the frame degrades.
Keep your originals. Compression is not reversible, and the settings that suit a web page are rarely the settings that suit a print.
Frequently asked questions
How do I compress an image to exactly 200 KB?
Use target-size mode and set 200. The tool searches for the highest quality that stays under your limit.
Why can it not reach my target size?
Usually because the image is too large in pixel dimensions. Resize it first — halving the width typically quarters the file size — then compress.
Which format compresses best?
WebP, by a clear margin over JPEG at matched quality. Use JPEG only when the destination will not accept WebP.
Why does my PNG become a JPG?
PNG is lossless and barely compresses. The default converts it to JPEG, which typically shrinks a screenshot by around 90%. Choose an explicit format if you need PNG preserved.
Does compressing repeatedly make files smaller?
No — it makes them worse. Each lossy cycle compounds the artefacts of the last. Always compress from the original.
Are my images uploaded?
No. All encoding happens in your browser, and nothing is transmitted.