Image

Compress Images Online

Make photos and screenshots smaller without making them look worse. Drop in JPG, PNG or WebP images, choose a quality level, and download lighter files for email, upload forms and websites. Compression runs in your browser, so your images are never uploaded.

How to compress an image

  1. Drop one or more images onto the tool.
  2. Pick a quality level or a target size.
  3. Compare the before/after file size.
  4. Download the compressed images.

Which quality setting should I use?

  • 80–85%: visually identical for most photos; a good default.
  • 60–75%: much smaller, fine for thumbnails and previews.
  • Below 60%: visible artefacts likely.

PNG is a lossless format, so the quality setting does not apply to PNG output; choose WebP or JPEG output for the biggest savings. For the biggest savings on the web, also convert to WebP with JPG to WebP or PNG to WebP.

Compress vs resize

Compression reduces file size while keeping the same pixel dimensions. Resizing reduces the dimensions themselves. A 4000-pixel photo shown at 800 pixels should be resized first with the Image Resizer, then compressed.

Why smaller images matter

Images are usually the largest files on a page. Lighter images improve loading speed and Largest Contentful Paint, and they get past email and form upload limits.

Private by design

PocketCvt tools run in your browser. Your files and text are processed on your own device and are not uploaded to our servers. No account is needed.

Why use this free compress image tool?

  • All processing happens locally in your browser. Your files are never uploaded to a server.
  • Several images at once, each with a before/after size readout.
  • Quality slider, or a target size in KB for JPEG and WebP output.
  • Keep the original format or convert to JPEG, WebP or PNG while compressing.
  • If re-encoding would make a file bigger, the original is kept.

Technical details

Each image is decoded and redrawn on a canvas at its original pixel dimensions, then re-encoded with the browser's built-in JPEG, WebP or PNG encoder. The same engine powers the Image Resizer.

Target size mode runs a binary search over the quality setting (up to eight encodes per image) and keeps the highest quality that fits. If even the lowest quality is too large, the tool tells you to resize first.

PNG is lossless, so PNG output ignores the quality setting; transparent images exported as JPEG get a white background because JPEG has no alpha channel. Metadata such as EXIF is not carried over.

Compress Images Online FAQ

Is image compression free?

Yes, with no sign-up, watermark or daily limit.

Are my images uploaded?

No. Compression happens on your device in the browser.

Will compression reduce quality?

At around 80% quality, the difference is usually invisible while the file is much smaller.

Which formats are supported?

JPG, PNG and WebP.

How do I get an image under a specific size, like 100 KB?

Turn on the target size option and enter the limit, or lower the quality step by step. If the file is still too big, resize the dimensions first.

Related free converters

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