Compress an image to an exact size

How it works

1. Choose or drop one or more images (JPG, PNG, HEIC, WebP or AVIF).
2. Type the maximum size in KB, or tap one of the common sizes.
3. Select Compress images. The bar under each result shows the new size against your limit.

The tool first lowers the JPG quality step by step to find the best quality that fits. Only if that is not enough does it reduce the pixel dimensions, a little at a time. That gives you the clearest image the limit allows.

Picking a size

• 20 KB or less: signatures and thumb impressions on application forms. See compress image to 20 KB.
• 50 KB: passport-style photos on most job and exam portals. See compress image to 50 KB.
• 100 to 200 KB: document photos, ID proofs and profile pictures. See compress image to 100 KB.
• 500 KB to 1 MB: email attachments and website images that should still look sharp.

Need a fixed width and height as well?

Many forms ask for exact pixel dimensions as well as a size limit. Use the photo and signature resizer, which sets both at once.

KB, MB and why your file may still be rejected

Websites count file sizes in two slightly different ways. Most operating systems use 1 KB = 1,024 bytes, while some portals check against 1 KB = 1,000 bytes. A file shown as 49.5 KB on your computer can be 50,688 bytes, which a strict portal reads as over a 50 KB limit. To be safe, aim about 5% below the limit, for example 47 KB for a 50 KB rule.

1 MB is 1,024 KB, so a 2 MB limit allows roughly 2,048 KB.

What really controls image file size

• Pixel dimensions: a 4000 × 3000 phone photo has 12 million pixels. Halving the width and height cuts that to 3 million, roughly a quarter of the data.
• Compression quality: lower JPG quality removes fine detail. Between 70% and 90% the difference is hard to see; below 50% blocks and smudges appear.
• Content: busy scenes, grass, hair and noise compress poorly. Plain backgrounds and documents compress well.
• Not DPI: the DPI value stored in a file does not change its size in KB. Only dimensions and compression do.

Sizes commonly asked for

Upload	Common limit	Tip
Signature	10 to 20 KB	Crop tightly around the signature first
Passport-style photo	20 to 50 KB	Crop to head and shoulders
ID proof or certificate image	100 to 300 KB	Set a maximum width of about 1200 px
Email attachment	1 to 2 MB per photo	Quality 80% keeps photos sharp

These are common examples, not official rules. Always follow the limits stated on the form you are filling in.

Troubleshooting

• The result looks blocky: the limit is too small for the image size. Enter a smaller maximum width so the compressor can keep quality higher.
• The file is below the minimum size: some forms reject files that are too small. Try a slightly higher target or use the photo and signature resizer, which handles minimum and maximum sizes together.
• The form wants exact pixel dimensions: use the photo and signature resizer instead, which sets dimensions and size in one step.

Questions

Related tools

• Compress image to 20 KB
• Compress image to 50 KB
• Compress image to 100 KB
• Resize image