Compress JPG images for faster websites

Drop a JPG in, get a smaller JPG out. Most photos come back 60 to 80 percent smaller with nothing you can see by eye.

Why JPG files are usually bigger than they need to be

JPEG is a lossy format, which means it throws away detail your eye is unlikely to miss in exchange for a smaller file. How much it throws away is a setting, and almost nothing sets it well. A camera writes JPEGs at quality 95 or higher because it does not know what you will do with the photo. A phone does the same. Photoshop's Save for Web defaults have not been right for a decade. The result is that a typical photo exported from a camera or a design tool is two to four times larger than it needs to be for a web page.

Compressing a JPG is mostly a matter of re-encoding it at a sensible quality. We default to quality 80, which is the setting most of the web has settled on as visually lossless for photographs. On a normal photograph, the difference between quality 95 and quality 80 is invisible at 100 percent zoom and cuts the file roughly in half. Below about 70 you start to see blocking in flat areas like skies and skin, which is why the slider exists and why we do not push it down for you.

What this JPG compressor actually does to your file

Three things. It re-encodes the image with an mozjpeg-quality encoder at the quality you choose. It strips metadata, which on a phone photo means the GPS coordinates, the camera model, the timestamp, and often an embedded thumbnail that can be tens of kilobytes on its own. And it writes the result progressively, so the image paints top to bottom as it loads rather than appearing all at once at the end.

It does not resize your image. If you upload a 6000 pixel wide photo, you get a 6000 pixel wide photo back, smaller in bytes. Resizing is the single biggest saving available on most sites, and it is a decision about layout that a compressor should not make for you. If your page displays an image 800 pixels wide, export it at 1600 pixels for retina screens and then compress it. That combination will beat any compressor working alone.

When to keep JPG, and when to move to WebP or AVIF

Keep JPG when you need the widest possible compatibility, including old email clients, older Android builds, and anything that has to open in software you do not control. JPEG has been readable everywhere for thirty years and it will keep being readable.

Move to WebP when you control the page. WebP is supported by every browser in current use and typically lands 25 to 35 percent smaller than a JPEG of the same visual quality. Move to AVIF when page weight is the thing you are optimizing hardest for and you can afford a slower encode. AVIF commonly beats JPEG by 50 percent or more on photographs. The honest way to ship either is a picture element with an AVIF source, a WebP source, and a JPEG fallback, so every browser gets the smallest file it can read. You can produce all three here by changing the output format and compressing the same image again, which costs you nothing extra.

JPG or JPEG, and does it matter

They are the same format. The three letter extension is a leftover from MS-DOS, which allowed only three characters, and Windows carried it forward. JPEG is the name of the committee that standardized it, the Joint Photographic Experts Group. Use whichever extension your tools produce. Web servers set the content type from the file, not the extension, and browsers read both without complaint.

JPEG questions

Does compressing a JPG reduce its quality?

Yes, technically, because JPEG is a lossy format and every re-encode discards some data. At quality 80, which is the default here, the loss is not visible to the eye on a normal photograph. If you need to be certain, compress a copy and compare the two at 100 percent zoom before you replace the original.

Can I compress a JPG without losing any quality at all?

Not with a re-encode. Truly lossless JPEG optimization only rearranges the existing data, which usually saves 5 to 10 percent. Almost everyone is better served by a quality 80 re-encode, which saves far more and looks the same. Keep your original file either way, since compression cannot be undone.

How much smaller will my JPG get?

Photographs straight from a camera or a phone typically come back 60 to 80 percent smaller. Images that have already been compressed once will save much less, sometimes almost nothing, because the detail has already been discarded.

Is there a file size limit?

The free tier accepts images up to 25 megabytes each and 30 images at a time, which is well above what most photo workflows produce. Paid plans raise both limits.