How to Compress an Image to 100 KB (or 50 KB, or 200 KB) Without Ruining It
Why image files get big, the order in which to shrink them, how JPEG, WebP and PNG differ, and how to hit a target size for forms and uploads.
Why forms ask for small images
Job portals, exam sites and government forms often limit uploads to 50 KB, 100 KB or 200 KB. A photo straight from a phone is usually 2 to 6 MB, so it needs to shrink by a factor of 20 or more. That is possible, but the order in which you shrink it matters.
What decides the file size
Three things set the size of an image file: how many pixels it has, which format it uses, and how hard it is compressed.
- Pixels: a 4000 by 3000 photo has twelve million pixels. Halving both sides leaves a quarter of them.
- Format: JPEG and WebP suit photos. PNG keeps every detail and is best for screenshots, logos and text.
- Compression level: for JPEG and WebP, a lower quality number gives a smaller file and less detail.
The best order: resize, then compress
Most people drag the quality slider first and end up with a blurry image that is still too big. A better order is to reduce the pixel count first, then lower the quality only as much as needed.
A form that shows your photo at 600 pixels wide does not need 4000 pixels. Resizing to 800 or 1000 pixels often gets a photo under 200 KB with quality still around 80, which looks clean.
JPEG, WebP or PNG
For photos and people, choose JPEG if the site may be fussy about formats, or WebP for a smaller file at the same look. Choose PNG only when you need sharp edges or transparency, and expect a larger file.
If a PNG screenshot is far over the limit, converting it to JPEG usually cuts it by more than half. Transparent areas turn white in JPEG, which is fine for most forms.
Reaching an exact target
Type the limit into the target size box of the Image Compressor, Resizer and Cropper. The tool tries different qualities and keeps the highest one that fits. If the image is still too big at the lowest quality, it reduces the dimensions a little and tries again.
Aim a little below the limit, for example 180 KB for a 200 KB rule. Some upload systems count a kilobyte as 1000 bytes, and others as 1024.
Passport and ID photos
These usually need a fixed shape, such as 35 by 45 millimetres, and a small file. Pick the 35:45 crop shape, drag the area so the face is centred, then set the target size. Always check the rules of the specific form, because some also require a minimum size in pixels.
Quality, privacy and metadata
Below roughly quality 50, JPEG shows blocky patches and banding around edges, so stop before that and resize more instead. Processing happens in your browser, so the photo is not uploaded. The result also drops camera details such as GPS location, which is a useful side effect when you share photos.