Lossy vs Lossless Compression for PDF Documents

Updated July 28, 2026 · 8 min read

Image compression comes in two flavours. Images are usually the reason a PDF becomes too large to email, so compressing them before inserting keeps the PDF small.

Recommended settings for PDF documents

SettingStarting point
FormatJPEG (WebP where accepted)
Widthabout 1600 px on the long edge
Quality78
File size200 KB or less

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

Lossy vs Lossless Compression

Lossless compression, as in PNG, keeps every pixel exactly and saves modest space. Lossy compression, as in JPEG and WebP, discards detail the eye barely notices and saves far more.

For photographs used for PDF documents, lossy is the practical choice. Save lossless formats for graphics where every pixel edge matters.

Step by step with TheCompressJPEG

  1. Open the compress JPEG to 200 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 1600 and the target size to 200 KB.
  4. Press Compress, check the result and download it.
Ready to try it? Compress your JPEG to 200 KB now. It's free and private.

Quick tips

  • Write a size limit slightly below the stated maximum to leave a margin.
  • Process private images locally rather than uploading them to unknown servers.
  • Crop out distractions so pixels go to the subject.
  • Use WebP where it is supported and you control the page.

FAQ

Can I compress images for e-learning courses without uploading them?

Yes. TheCompressJPEG runs entirely in your browser, so your images never leave your device.

Is WebP accepted for e-learning courses?

It depends on the platform. JPEG is the safest choice when you are not sure.

What size should an image be for e-learning courses?

A practical default is about 1600 pixels wide and 200 KB or less, unless the destination states its own limits.

Wrapping up

For PDF documents, the reliable recipe is simple: resize to around 1600 pixels, compress at quality 78 or to a 200 KB target, and check the result before you upload. Keep the original so you can always start again.

Related guides