Compress Images
Compress many images at once. Set the quality, maximum size and target size (KB) and each image is fitted automatically.
PNG is lossless, so its size may not drop much. Switch to JPG/WebP or lower the maximum size to shrink more. GIFs are processed as their first frame only.
How to use
- Upload several images.
- Choose output format, quality, maximum size and target size, then start.
- Check how much was saved and download each file or a ZIP.
View detailed guide
What this tool does
Compresses many images at once to reduce their size. Set the quality, the maximum long side and the target size (KB) and each image is adjusted automatically.
Steps
- Drop images or click to upload them. You can upload many at once.
- Choose the "Output format". The default is "Keep original format". To shrink more, choose JPG or WebP.
- If needed set the "Quality", "Target size" and "Max longest side".
- Press "Start". When done the list shows "original size → result size (change)" and the total savings.
- Download one by one with each row's "Download", or if at least 2 succeeded use "Download all as ZIP".
Settings
- Output format: "Keep original format" saves JPG as JPG, WebP as WebP and others (PNG, GIF, BMP...) as PNG. Choosing JPG or WebP makes every file that format.
- Quality (10-100): lower means a smaller file and lower quality. JPG and WebP only. The default is 80.
- Target size (KB): quality is lowered automatically for each image so it fits. JPG and WebP only.
- Max longest side (px): if the longer side is larger, the image is reduced keeping the ratio. Small images are not enlarged. This is the most effective way to cut size.
- Background color: fills transparent parts when saved as JPG.
- Keep original if the result is larger: when on (default), a file that did not get smaller is returned as the original and marked "kept original".
How it works
Each image is drawn on a browser canvas; if the long side exceeds the maximum it is halved repeatedly until it is within 2x of the target and then fitted to it. Then it is encoded again in the chosen format and quality. With a target size, quality is adjusted by binary search to find the highest quality that fits. PNG is lossless, so lowering quality does not shrink it; reduce the size or switch to JPG/WebP for a big saving.
Good to know
- A GIF is processed using only its first frame; with "Keep original format" it is saved as PNG.
- Result files are named "originalname_compressed.extension". Files whose original was kept keep the original name.
- Results are gone when you close the tab.