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Compress image to 300 KB

Set the budget, and the encoder is searched for the best quality that fits under 300 KB. On your device — the image is never uploaded.

  • 0 uploads
  • No limits
  • No signup
  • Works offline

Where a 300 KB limit comes from

Nobody chooses 300 KB for fun. If you are here, a form told you to, and the form probably did not explain how. These are the places this particular number turns up:

  • Web page hero images where page weight matters
  • Portfolio uploads with a per-file cap
  • Marketplace listings with high-resolution requirements

At 300 KB even a detailed 2000-pixel photograph — foliage, crowds, textured fabric — stays clean.

What to expect at this size

Image compression is a trade between three things: pixel dimensions, visual quality and file size. Fix any two and the third follows. Because you have been handed a fixed file size, the question becomes how to split the remaining budget between dimensions and quality.

This tool spends it on dimensions first. A 1000-pixel image at quality 55 almost always looks better than a 500-pixel image at quality 95, because the eye is far more forgiving of compression artefacts than of missing resolution. Only when quality has nothing left to give does the resolution come down.

Comfortable for anything that is not going to print.

Getting a better result

Three things reliably help when the budget is tight:

  • Crop before compressing. Every pixel you keep costs bytes. A tightly framed portrait at 300 KB looks far better than a full-body shot squeezed into the same space. The cropper hands its result straight to this tool.
  • Start from the highest-quality original you have. Compressing an image that has already been through WhatsApp compounds the damage. Go back to the file straight off the camera.
  • Prefer WebP if the form allows it. At the same file size WebP holds noticeably more detail than JPEG. Most official forms still want JPG, but it costs nothing to check.

Other common targets

10 KB · 20 KB · 30 KB · 50 KB · 100 KB · 150 KB · 200 KB · 500 KB

How it works

  1. 01Add your imageDrop it on the page, click to browse, or paste from the clipboard.
  2. 02The 300 KB target is already setYou landed on this page, so the budget is filled in. Change it if you need something different.
  3. 03The search runsThe encoder is run repeatedly, binary-searching quality for the best result that still fits under 300 KB.
  4. 04Compare, then downloadDrag the before/after slider to see what the compression cost before you commit.

Questions people actually ask

Will my photo still look acceptable at 300 KB?
At 300 KB even a detailed 2000-pixel photograph — foliage, crowds, textured fabric — stays clean. Comfortable for anything that is not going to print.
Is the result exactly 300 KB?
It lands within about 5% below 300 KB, and never above it. Going over would defeat the point — a form that says "maximum 300 KB" rejects a file of 301 KB without explanation.
What if the target is impossible at full resolution?
Quality is reduced first, because keeping pixels usually looks better than keeping precision. Only when the lowest acceptable quality still overshoots does the image get scaled down a step, and then the quality search starts again at the smaller size.
Does it work on PNG?
PNG is lossless, so it has no quality dial to search — hitting an exact byte target with PNG means resizing. For a specific KB budget, JPG (for photographs) or WebP (for anything modern) will give you a much better-looking result. The tool defaults to keeping your original format, so switch it if you need to.
Is my image uploaded?
No. Every encode in the search runs on your own device, in a background thread, using WebAssembly builds of MozJPEG and libwebp. Nothing is transmitted, which is also why there is no limit on how many images you can do.
The form also wants specific pixel dimensions. What order should I do things in?
Resize first, compress second. Resizing after compressing throws away the work the compressor just did. Use the resizer, then chain straight into this tool from the result screen.

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