Compress image files without ruining them
Compression removes detail your eyes barely notice. The trick is stopping before the changes become visible. FileKiwi does this for you with a smart quality search on JPG and WebP files: it tests settings and keeps the version that looks close to the original while weighing far less.
PNG works differently. It is a lossless format, so the savings come from reducing the number of colors in the image. This happens on the FileKiwi server, and the file is deleted right after processing. Screenshots, charts and logos usually shrink a lot this way.
A few habits help every time:
- Crop first. Removing empty sky or background cuts the size before compression even starts.
- Compress the original. Each new save of a JPG loses a little more, so start from the best copy you have.
- Pick the right format. Photos belong in JPG or WebP. Graphics with sharp edges or transparency fit PNG better.
Which format gives the smallest file?
The format often matters more than any setting. Here is a quick guide for choosing the output.
| Format | Best for | Keep in mind |
|---|---|---|
| JPG | Photos for email, forms and social media | Opens everywhere, no transparency |
| WebP | Photos and graphics on websites | Usually smaller than JPG at similar quality, but some older apps cannot open it |
| PNG | Screenshots, logos, images with transparency | Large for photos, great for flat colors and text |
If a PNG photo stays too heavy, switch the output to JPG or WebP. You can also convert ahead of time with PNG to JPG.
When smaller pixels help more than compression
A 4000 pixel wide photo is far bigger than any screen needs. If a picture will only appear in a blog post or a chat, lowering its dimensions with Resize Image before compressing gives the biggest drop in size. For format specific advice, see Compress JPG and Compress PNG.
