Two ways to compress
The tool above has two modes, and they suit different jobs:
- Quality — you choose a quality level (70% by default) and every image is re-encoded at that setting. Use it when you just want lighter files for a website, a chat or an archive and don't care about an exact number.
- Target size — you type a limit in KB and the tool finds the highest quality that still fits under it. Use it when a form, portal or mailbox gives you a hard cap.
Both modes accept a whole batch. With several files you get a list of before/after sizes and a single ZIP to download.
What happens to each format
| You drop | Quality mode | Target size mode |
|---|---|---|
| JPG | Stays JPG | Stays JPG |
| WebP | Stays WebP (if your browser can encode it) | Stays WebP (same condition) |
| PNG with transparency | Stays PNG | Stays PNG — only the pixel size can shrink |
| PNG without transparency | Stays PNG | Becomes JPG, which is far smaller for photos |
| Other formats your browser can open | Become JPG | Become JPG (PNG if transparent) |
PNG is lossless: a quality slider can't do much for it. That's why a PNG that shrinks poorly in quality mode often drops dramatically in target mode — if it has no transparent pixels, it's re-saved as JPG. If you need to keep the transparency but want a smaller file, PNG to WebP is usually the better route.
How target size mode gets there
Sizes are counted in decimal kilobytes: a 200 KB target means 200,000 bytes. That keeps the file under the limit whether the website counts 1 KB as 1,000 or 1,024 bytes. (The result panel counts in 1,024-byte units, so a file right at the limit shows a couple of percent lower — 200,000 bytes appears as 195 KB.)
The search works in two steps:
- It tries quality levels between 92% and 40% and keeps the highest one that fits.
- If even 40% is too big, it reduces the width and height and tries again, instead of going below 40%, where JPG turns into visible blocks.
So a small target on a big photo always gives you a smaller picture, not a ruined one. If a file can't reach the target at all (rare, mostly tiny limits on PNGs with transparency), you'll see a warning next to the result.
How small can a photo realistically get?
These are rough figures for an ordinary phone photo at decent quality; busy scenes (leaves, gravel, crowds) need more bytes, plain backgrounds fewer.
- 50 KB — around 700–900 px on the long side
- 100 KB — around 1,000–1,300 px
- 250 KB — around 1,600–2,000 px
- 1 MB — 3,000 px or more
- 2 MB and up — usually the full 12-megapixel original
For the most common limits there are ready-made pages: 50 KB, 100 KB, 200 KB, 500 KB, 1 MB and 2 MB.
Resize first for a cleaner result
File size depends far more on pixel count than on the quality setting. A 4,000 × 3,000 photo has twelve times the pixels of a 1,200 × 900 one. If the image will only be seen on a screen, set Max side (for example 1,600 or 2,000 px) before compressing — you'll get a smaller file at a higher quality level than squeezing the full-size photo. For exact dimensions, use Resize Image first.
Cropping helps too: every pixel of empty wall or sky you crop away is a pixel you don't have to store.
Common questions
- "The file barely got smaller." It was probably already well compressed, or it's a PNG with transparency. Lower the quality, set a max side, or switch to target size mode.
- "Can it make an image bigger?" No — compression only reduces. To increase the pixel size, use Resize Image.
- "My iPhone photo won't open." Convert it with HEIC to JPG first, then compress.
- "Is the location data kept?" Re-encoding writes a new file without the original EXIF block. To check or strip it on its own, use the EXIF viewer or Remove Metadata.
Everything runs in your browser: the images are never uploaded, so even a large batch is limited only by your device's memory.