How to Resize Images for Marketplace Ads

Updated October 8, 2026 · 6 min read

Resizing is the single biggest lever for file size. 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.

How to Resize Images

File size scales roughly with the number of pixels. Shrinking a 4000 by 3000 photo to 1600 pixels wide removes most of the data before compression even begins.

Keep the aspect ratio locked so nothing looks stretched. Our compressor scales proportionally when you set a maximum width, so you only need to enter one number: 1600.

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

  • Always keep the original file and compress a copy.
  • Use JPEG for photos and PNG for logos and line art.
  • Name files descriptively with lowercase words and hyphens.
  • Check the result on a phone, where most people will see it.

FAQ

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.

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.

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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