Why compress an image to 20KB?
A 20KB limit for images is more common than you might think. Many government portals, job application forms, university admissions systems and ID verification platforms require profile photos or scanned documents to be under 20KB. Email signatures, website favicon images and app icons also typically need to be very small.
The challenge is that even a compressed photo from a phone camera is typically 1–5 MB — 50 to 250 times larger than the 20KB limit. Getting an image below 20KB requires a combination of resolution reduction and quality compression, applied correctly.
The good news: it is completely achievable without any loss in visual recognition — especially for profile photos and documents where print-level sharpness is not required.
How to compress an image to 20KB — step by step
For profile photos on government portals, 400px width at 65% JPG quality almost always produces a file under 15KB while keeping the face clearly visible and recognizable.
Best settings for 20KB output
Different image types need different settings to reach 20KB. Here is a reference table:
| Image type | Resize to | Quality | Format | Expected output |
|---|---|---|---|---|
| Profile photo (face) | 400–600px | 65% | JPG | 8–18KB |
| Document scan | 800px | 60% | JPG | 10–20KB |
| Product photo | 600–800px | 60% | JPG | 12–20KB |
| Logo / graphic | 400px | 70% | WebP | 5–15KB |
| Screenshot | 800px | 65% | JPG | 10–20KB |
These are typical values — actual output depends on the complexity and content of your specific image. Images with lots of color variation (like busy outdoor photos) will be larger than simple images with flat colors.
Which format works best under 20KB?
JPG is the best format when you need to reach very small file sizes like 20KB. JPG's lossy compression is extremely efficient at low quality settings, and most platforms that require images under 20KB specifically require JPG format.
WebP can achieve even smaller file sizes than JPG at the same visual quality — about 25–35% smaller. However, some older systems and government portals only accept JPG files. If the platform accepts WebP, use it for the smallest output.
PNG is a lossless format and is not suitable when you need very small files. A PNG version of a photo is always significantly larger than the equivalent JPG. Only use PNG when transparency is required and the platform accepts it.
If a form says "JPG only under 20KB", convert your image to JPG first. PNG files cannot be compressed to 20KB without losing significant quality in most cases.
Tips to reliably get under 20KB
1. Resize dimensions first — this has the biggest impact
The pixel dimensions of an image are the biggest driver of file size. A 4000x3000 pixel photo has 12 million pixels. Resized to 800x600, it has only 480,000 pixels — 25 times fewer. Even before any quality compression, this resize alone reduces file size dramatically. Always resize first when targeting very small file sizes.
2. Use 60–70% quality for JPG — this is still visually acceptable
Many people are surprised that an image at 60% JPG quality still looks perfectly clear and usable, especially at small display sizes like profile photos. At 400px wide and 65% quality, a face photo looks completely sharp and recognizable. The difference from a 90% quality version is not visible at this size.
3. Convert PNG to JPG before compressing
If you start with a PNG file, convert it to JPG as part of your compression. CompressAll lets you set the output format to JPG regardless of the input format. A PNG photo that is 2MB can often be reduced to under 15KB as a JPG at 65% quality and 600px width.
4. For documents, scan at lower resolution
Documents scanned at 300 DPI or more produce very large files. For online forms, a scan at 150 DPI is sufficient for readability and produces a much smaller file. Combine with JPG compression at 65% quality and 800px width to reliably get under 20KB.
5. If still over 20KB, reduce dimensions further
If your image is still over 20KB after the first compression, reduce the resize dimension by 100–200px and try again. Going from 800px to 600px can reduce file size by a further 30–40%. Repeat until you get under the target.