Shrink images without uploading them
Large photos straight from a camera or phone can be 5 to 15 megabytes, far too big for email, forms and fast web pages. This compressor re-encodes your JPG, PNG or WebP image at the quality you pick, shows the size before and after, and lets you download the smaller file. Nothing is uploaded: the work happens in your browser, so even private photos stay private.
Compress to an exact size: 20KB, 50KB, 100KB, 200KB or 1MB
Many upload forms do not ask for "good quality", they state a hard limit: a passport photo under 200KB, a signature under 50KB, an attachment under 1MB. Guessing slider positions until you sneak under the line wastes time, so this tool also offers Target size mode. Pick a preset or type your own limit in KB, and the compressor searches quality settings automatically, testing encodes until it finds the highest quality that still fits under your target. Only if even the lowest quality is too big does it step the dimensions down, and the result panel always reports the size actually achieved next to the target you set, so you know before you upload anywhere else whether the file will pass.
When smaller images matter
- Websites: image weight is the biggest factor in page load time, and load time affects both visitors and search rankings.
- Email and forms: most inboxes and application portals cap attachments at sizes phone photos easily exceed.
- Storage and sharing: compressed copies are quicker to send and cheaper to store.
Need a different format instead? The Image Converter switches between JPG, PNG and WebP, and the Image Resizer changes the pixel dimensions.
How compression works under the hood
When you add a photo, your browser decodes it into raw pixels, the same grid of colored dots you see on screen. The compressor then draws those pixels onto a canvas and asks the browser encoder to write them back out at the quality level you set. For JPEG and WebP that encoder uses lossy compression. It groups nearby pixels into small blocks, keeps the broad shapes and colors your eyes notice most, and discards fine detail your eyes are poor at seeing, especially sharp color changes in busy areas like grass, hair and fabric. Lowering the quality tells the encoder to discard more, which is why files shrink so fast at first and then show visible softness or blocky patches once you go too far. PNG works differently. It is lossless, so the encoder only looks for repeated patterns to store more efficiently, and the quality slider has no effect on the result.
Practical tips for better results
- Resize before you compress: a photo that will only ever display at 1200 pixels wide gains nothing from staying at 4000 pixels. Shrinking dimensions first often saves more than any quality change.
- Compress once, from the original: compressing an already compressed JPEG discards detail a second time. Always start again from the camera original if you want to try a different setting.
- Check at full size: zoom to 100 percent and look at faces, text and straight edges. If those still look clean, most viewers will never notice the compression.
- Match the format to the job: WebP for your own website, JPEG for maximum compatibility with forms and older software, PNG only when you need transparency or pixel perfect graphics.
- Keep an untouched master: save the original somewhere safe and treat the compressed file as a delivery copy you can regenerate any time.
A worked example
Say you have a phone photo of a birthday cake that is 4032 by 3024 pixels and 6.8 MB, and a school application form that accepts attachments up to 2 MB. At 80 percent quality as a JPEG, the same photo comes out at roughly 1.4 MB, well under the limit, and on screen it is hard to tell from the original. If you also resize a copy to 1600 pixels wide for a blog post and export it as WebP at 75 percent, the file drops to around 180 KB. That version loads almost instantly even on a slow mobile connection, while the 1.4 MB version stays on file for the application. Two minutes of work, two files, each sized for its purpose.
Common mistakes to avoid
- Crushing screenshots to JPEG: text and user interface edges smear badly at low quality. Use PNG or WebP for anything with sharp lines and small text.
- Chasing the smallest possible file: saving an extra 50 KB is not worth a photo that looks muddy. Judge the result with your eyes, not just the percentage saved.
- Compressing the compressed copy again and again: each lossy pass throws away more detail, so quality slides downhill quickly after two or three rounds.
- Expecting PNG to shrink with the slider: PNG ignores quality settings. If a PNG stays large, convert it to WebP or JPEG instead, or reduce its dimensions.
- Deleting the original: compression is one way. Once detail is discarded you cannot get it back, so never overwrite your only copy.