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Image Compressor

Recompress an image to a smaller JPEG entirely in your browser, with a quality slider you control. Your file never leaves your device.

How to use this tool

  1. 1

    Click the file input and choose an image (JPG, PNG, or WebP).

  2. 2

    Drag the quality slider — lower percentages produce smaller files.

  3. 3

    Compare the original and compressed sizes, and the percentage saved, shown below.

  4. 4

    Click Download to save the recompressed JPEG.

How browser-based image compression works here

Most of a web page's weight is images, so shrinking them is usually the single biggest performance win you can make — smaller images load faster, cost less bandwidth, and directly improve the Largest Contentful Paint (LCP) metric that Google's Core Web Vitals measure. This tool draws your selected image onto an HTML canvas and re-exports it as a JPEG at the quality level you pick (10–100%). JPEG uses lossy compression: as you lower the quality, the encoder discards fine high-frequency detail the eye barely registers, and the file shrinks accordingly. Two things are worth knowing because they follow from how the tool is built. First, the output is always a JPEG, regardless of whether you fed it a PNG or WebP — so a PNG with a transparent background comes out with that transparency flattened (typically to black), which makes this the wrong tool for logos or images that need an alpha channel. Second, it recompresses at the original pixel dimensions; it does not resize. For the largest savings you'll often want to scale a 4000px photo down to the width it's actually displayed at first, using a resizer, then compress. For everyday photos and JPEG hero images, dropping quality to 70–80% usually cuts the file dramatically with no visible difference.

Common use cases

  • Shrink a large JPEG hero or banner to improve LCP and Core Web Vitals.

  • Compress holiday or event photos before emailing or messaging them.

  • Reduce product photos for an ecommerce listing where the source files are huge.

  • Lighten blog-post photography so pages load faster on mobile.

  • Quickly check how much smaller a photo gets at 60% vs 80% quality before committing.

  • Flatten and compress a screenshot that doesn't need transparency.

Frequently asked questions

Is my image uploaded anywhere?
No. The image is read and recompressed entirely in your browser with the canvas API — nothing is sent to a server, so private photos and screenshots never leave your device.
What output format do I get?
Always a JPEG, even if you upload a PNG or WebP. JPEG is ideal for photographs. If you specifically need WebP or a transparent PNG out, use a format-specific converter instead.
Will a transparent PNG keep its transparency?
No — because the output is JPEG, which has no alpha channel, any transparent areas are flattened (usually to black). Don't use this on logos, icons, or UI assets that rely on transparency; it's built for photographic images.
Does it resize the image?
No. It recompresses at the original pixel dimensions and only changes quality. For the biggest wins, resize an oversized image down to its real display width first, then compress — combining the two saves far more than either alone.
What quality setting should I use?
For web photos, 70–80% is usually visually identical to the original at a fraction of the size. Go lower for thumbnails or background images where some softness is acceptable; stay higher for detailed imagery viewed full-screen.
Why did my already-optimized image barely shrink (or grow)?
If the source is a small, already-compressed JPEG, re-encoding it offers little to gain and can occasionally add bytes. Compression helps most on large, lightly-compressed originals straight from a camera or design tool.

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