Compress Image Online

Reduce image file size by up to 90% without visible quality loss. Perfect for websites, email, and social media.

1. Upload Image

Why Compress Images?

Faster Websites

Smaller images load faster, improving user experience and Google PageSpeed scores.

Save Storage

Reduce storage costs on servers, cloud drives, and your device.

Faster Sharing

Share images faster via email, WhatsApp, or social media without size limits.

What the Quality Slider Is Actually Doing

JPEG compression does not simply 'reduce quality' in a general way. It breaks the image into 8 × 8 pixel blocks, converts each block from pixel values into frequency information, and then divides those frequencies by numbers taken from a quantization table. High frequencies — fine texture, sharp edges, small details — get divided by large numbers and often round down to zero, which is where the space saving comes from.

The quality slider scales that table. At 90 the divisors are small and almost everything survives. At 40 they are large and entire categories of detail vanish. This is why the damage from over-compression looks so distinctive: you see the 8 × 8 blocks themselves appear in smooth areas like sky and skin, because within each block there is no longer enough information to describe a gradient.

It also explains why compression behaves so differently depending on content. A photograph of foliage is nearly all high-frequency detail and resists compression; a studio portrait against a plain backdrop is mostly low-frequency and compresses beautifully. Two images at identical settings can differ threefold in size for this reason alone.

Choosing a Quality Setting

Rough guidance for photographic content. Graphics and screenshots tolerate compression far worse.

QualityVisual resultSuitable for
95–100Indistinguishable from originalArchival copies, print masters
85–90No visible loss in normal viewingPortfolio work, client delivery
75–85Excellent — the usual sweet spotWebsites, social media, email
60–75Slight softening on close inspectionThumbnails, hitting size limits
40–60Visible artifacts in flat areasOnly when a hard limit forces it
Below 40Obvious blocking and colour bandingBest avoided entirely

Compression Damage Accumulates

Every time a JPEG is opened, changed and saved again, it goes through the whole quantization process afresh — on top of the losses already baked in. Ten rounds of saving at quality 85 looks considerably worse than one round at 60, even though 85 sounds like the safer number. This is generation loss, and the way to avoid it is to keep an untouched original and always export from that rather than repeatedly editing and re-saving the compressed copy.

Compress or Resize?

They solve different problems, and reaching for the wrong one is the most common mistake.

Compress when
  • The dimensions are already correct for where the image will be used
  • You need a modest reduction — say 40–60% smaller
  • The image is displayed at full size and must stay sharp
  • You are optimising a batch of already correctly-sized web images
Resize instead when
  • The image is far larger than it will ever be displayed
  • You need a dramatic reduction, such as a phone photo down to 100KB
  • Compression alone is not getting you under the limit
  • You are uploading a 4000px photo to fill a 600px slot

Formats Respond Very Differently

Compressing a PNG is a fundamentally different operation from compressing a JPEG. PNG is lossless, so 'compressing' it means finding a more efficient lossless encoding — reducing the colour palette, optimising how rows are filtered — and the savings are usually modest, perhaps 10–30%. Nothing is discarded.

JPEG and lossy WebP genuinely discard information, which is why their savings are so much larger. WebP tends to reach a given visual quality in roughly 25–35% fewer bytes than JPEG, so if the destination is a website and you can serve WebP, converting will usually beat compressing the JPEG harder.

For screenshots, logos and anything containing text, the right answer is usually not to apply lossy compression at all. Those images belong in PNG or lossless WebP, where the letterforms stay clean; pushing them through a JPEG encoder produces visible coloured fringing around every edge.

Frequently Asked Questions

How do I compress an image for email?

Upload your image, set the quality to around 70–80%, and download the compressed version. Most email clients recommend images under 1MB. Our compressor can reduce most photos to well under that limit.

Can I compress an image to a specific file size like 100KB?

Yes — lower the quality slider until the estimated file size reaches your target. For very small targets (under 50KB), also consider reducing the image dimensions first.

Will compressing reduce visible quality?

At quality settings of 75–85%, the difference is invisible to the human eye while file size drops by 60–80%. Below 60% quality, some artifacts may become visible.

What formats can I compress?

JPG, PNG, and WebP are supported. JPG compresses best for photos; PNG is better for graphics and logos.

Is my image stored after compressing?

No. Your image is processed immediately and deleted from our servers. We never store or share your files.