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Image Compressor

Make JPEG, PNG or WebP images smaller in your browser, by quality or to a target size, with no upload.

By Nitin Raturi · Last reviewed

Input

How to use the Image Compressor

Make an image file smaller in your browser, by quality or to a target size.

  1. Choose an image.
  2. Choose JPEG or WebP.
  3. Set a quality, or a maximum size in KB.
  4. Compare the sizes and preview, then download.

Good to know

  • Nothing is uploaded; the image stays on your device.
  • To shrink further, reduce the pixel size with the image resizer.

Make an image file smaller by quality or to a target size, keeping its pixel size.

Runs in your browser. Nothing you type is uploaded or saved in the link.

Image

The photo or picture to compress. It is opened in your browser and never uploaded.

How to fill it in

  • Choose a JPEG, PNG, WebP, GIF or BMP file up to 30 MB.
  • Very large images (over 40 megapixels) are refused to protect your phone’s memory.

Example

A 2,000 KB phone photo saved at 500 KB is 75% smaller.

Save as

The file type of the compressed image.

How to fill it in

  • JPEG: works everywhere; transparent areas become white.
  • WebP: usually smaller at the same quality and keeps transparency, but some older apps cannot open it.

Compress by

Pick a quality yourself, or give a size and let the tool find the highest quality that fits.

How to fill it in

  • Quality: you choose from 5 to 100.
  • Target size: you give a maximum in KB.

Quality

How much detail the encoder keeps. Lower means a smaller file and more visible blur or blocks.

How to fill it in

  • Enter a whole number from 5 to 100.
  • Around 70 to 85 suits most photos.

Keep in mind: Re-saving an already compressed image at high quality can make it larger: 100 KB became 125 KB in one test case.

Result

Choose an image to see the result here.

ChangelogHow we test this toolEmbed this tool

How this calculator works

  1. Step 1Open locallyNo uploadThe file is decoded on your device.
  2. Step 2Same pixelsW × HWidth and height stay the same.
  3. Step 3Re-encodeJPEG or WebPAt your quality, or the highest that fits a size.
  4. Step 4CompareBefore / afterBoth sizes and a preview, then download.

JPEG and WebP are lossy formats: they drop detail the eye notices least. A lower quality drops more, so the file shrinks, but blur and blocky edges appear sooner.

In target-size mode the tool tries the top quality first, then halves the range repeatedly, keeping the best result it actually measured within your limit.

Worked example

A phone photo compressed
Saved
(original − compressed) ÷ original × 100
  1. Original2,000 KB
  2. Compressed500 KB
  3. Saved(2,000 KB − 500 KB) ÷ 2,000 KB75%

The compressed file is 4 times smaller. Results depend on the picture: detailed photos compress less than plain graphics.

JPEG or WebP

  • JPEGWorks everywhereTransparent areas become white.
  • WebPOften smallerKeeps transparency; some older apps and sites cannot open it.

Read the result

The status line says how much smaller (or larger) the file became; the preview shows the quality before you download.

Re-saving an image that was already compressed can make it larger at high quality: 100 KB can become 125 KB. Lower the quality if that happens.

Assumptions and limits

  • PrivateNothing is uploaded; the image stays on your device.
  • Metadata droppedCamera details and location (EXIF) are not kept.
  • Size limitsUp to 30 MB and 40 megapixels per image.
  • 1 KB = 1,000 bytesSome forms count 1,024; the byte count is shown too.

Encoders differ between browsers, so the same settings can give slightly different sizes in Chrome, Firefox and Safari.

Compression cuts file size. Resizing and converting to PDF are separate steps.

To change an image’s dimensions, use the image resizer. For exam and job forms, the photo and signature resizer has preset sizes, and image to PDF combines pages.

Common mistakes

  • Mistake: Compressing the same JPEG again and again.

    Instead: Start from the original each time to avoid adding blur.

  • Mistake: Using quality alone to hit a tiny size.

    Instead: Reduce the pixel size first with the image resizer.

  • Mistake: Saving a logo with a transparent background as JPEG.

    Instead: Use WebP to keep the transparency.

Checking the method

The size search is shared with, and tested by, the Photo & Signature Resizer; savings are re-checked by an independent script.

An independent Python script recomputes every savings figure and file name with exact fractions.

Read how we test our calculators, or browse more everyday tools.

Frequently asked questions

Is my image uploaded?

No. It is opened and compressed in your browser, and the result is saved straight to your device.

How much smaller will my image get?

It depends on the picture and quality. In the worked example a 2,000 KB photo becomes 500 KB, 75% smaller.

How do I compress an image to a specific size in KB?

Choose Target size and enter the maximum. The tool finds the highest quality that fits. If it cannot, reduce the pixel size first.

Should I choose JPEG or WebP?

JPEG opens everywhere. WebP is often smaller and keeps transparency, but some older apps and upload forms do not accept it.

Why did my image get bigger?

An image that was already compressed can grow when saved again at high quality. Lower the quality.

Sources and methodology

The formulas are standard time-value-of-money results. We check every figure against golden values worked out independently, by closed form and by month-by-month simulation; see the methodology.

Written and maintained by Nitin Raturi, a software engineer (about the author). Last reviewed 3 Nov 2026; next review due by . Found an error? Tell us.

Changelog

  • : Initial release.

  • Image Resizer

    Resize images by longest side, percentage or width and height, in your browser, with no upload.

  • Image to PDF

    Turn photos, scans and screenshots into one PDF in your browser, with no upload.

  • Photo & Signature Resizer

    Resize and compress a photo or signature to the pixels and KB an exam or job form asks for, in your browser.