JPEG vs PNG for Signature Uploads

Updated June 29, 2026 · 7 min read

Choosing the wrong format can make a file five times larger than it needs to be. Signature images are simple black-on-white marks, so they can be very small while staying perfectly legible.

Recommended settings for signature uploads

SettingStarting point
FormatJPEG (WebP where accepted)
Widthabout 300 px on the long edge
Quality60
File size20 KB or less

These are practical defaults. If the platform or form you are using publishes its own limits, follow those instead.

JPEG vs PNG

JPEG is built for photographs with smooth gradients and noise. PNG is built for flat colours, sharp text and transparency. Saving a photo as PNG usually produces a much bigger file with no visible benefit.

For signature uploads, use JPEG for photos and PNG only for logos, screenshots with lots of text, or images that need a transparent background. You can convert a PNG photo to JPEG here and often cut its size dramatically.

Step by step with TheCompressJPEG

  1. Open the compress JPEG to 20 KB tool, or the main compressor for custom settings.
  2. Drop in your image. Nothing is uploaded; it is processed in your browser.
  3. Set the maximum width to 300 and the target size to 20 KB.
  4. Press Compress, check the result and download it.
Ready to try it? Compress your JPEG to 20 KB now. It's free and private.

Quick tips

  • Check the result on a phone, where most people will see it.
  • Use consistent dimensions for a set of related images.
  • Resize before you compress; it improves quality at any file size.
  • Write a size limit slightly below the stated maximum to leave a margin.

FAQ

How do I compress many images for e-learning courses at once?

Drop all of them into the tool together and use Download all to get a single ZIP.

What JPEG quality should I use for e-learning courses?

Quality around 78 keeps photos looking natural while cutting file size substantially.

Will compressing reduce image quality for e-learning courses?

Some detail is removed, but at sensible settings the difference is not visible at normal viewing size.

Wrapping up

For signature uploads, the reliable recipe is simple: resize to around 300 pixels, compress at quality 60 or to a 20 KB target, and check the result before you upload. Keep the original so you can always start again.

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