Common Mistakes When Compressing Images for Marketplace Ads

Updated March 22, 2026 · 8 min read

A few habits cause most of the blurry or oversized images we see. Classified and marketplace ads benefit from several quick-loading photos rather than one slow, heavy one.

Recommended settings for marketplace ads

SettingStarting point
FormatJPEG (WebP where accepted)
Widthabout 1600 px on the long edge
Quality78
File size300 KB or less

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

Common Mistakes When Compressing Images

Compressing the same JPEG again and again stacks artefacts each time, so always work from the original. Setting quality very low on a huge image gives a small file that looks muddy; resizing first is better.

Another mistake is ignoring orientation. Phones store rotation in metadata, and some tools drop it, leaving sideways photos. Our tool applies the correct orientation before compressing, so what you see is what you get for marketplace ads.

Step by step with TheCompressJPEG

  1. Open the compress JPEG to 300 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 300 KB.
  4. Press Compress, check the result and download it.
Ready to try it? Compress your JPEG to 300 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 marketplace ads, the reliable recipe is simple: resize to around 1600 pixels, compress at quality 78 or to a 300 KB target, and check the result before you upload. Keep the original so you can always start again.

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