The smallest file that still looks like the original
Measured, in your browser, no upload. Every result carries an SSIM value against your source.
Drag an image here
or paste from the clipboard (Ctrl+V / ⌘V)
JPEG, PNG or WebP · the image stays on your device
In three steps
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Choose an image
Drag, click or paste. The file stays on your device.
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Pick a preset
Website, target size or platform. Each preset names its origin.
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Check the result and download
The measured quality value is shown — also when it comes out badly.
Why this tool works differently
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Measured, not claimed
A compression slider tells you what the encoder was set to. The value here tells you what became of your image — also when it comes out badly.
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Nothing leaves your device
Decoding, measuring and encoding run in your browser. There is no counterpart that receives an image.
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Every value names its origin
Each preset states whether its numbers come from retrieved platform documentation or were set by this project itself — with source and check date. The overview lists them all.
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Sometimes the answer is: do nothing
If no re-encode is at least two percent smaller than your source, you get it back unchanged. In our test series that was the case for 0 of 20 images.
What came out on our own test corpus
- 27.5 % less across all 20 images together
- 43.8 % per image, median
- 0.98 quality target, held in every run
20 images, quality target SSIM ≥ 0.98, with no target size and no scaling: from 15.1 MB to 11.0 MB, that is 27.5 % less. No run missed the quality target, and none produced more bytes than its source. How it is measured, and where the method is imprecise.
All tools
By file size
- Compress an image to 500 KB Get an image under 500 KB without uploading it. Every result carries a measured quality value against your source.
- Compress an image to 100 KB Get an image under 100 KB without uploading it — and a straight answer when that is not possible for this image without visible loss.
- Compress an image to 1 MB Get an image under 1 MB without uploading it. The target size at which even large photos usually keep their quality target.
By format
- Convert JPG to WebP Convert JPG to WebP in your browser. The tool measures both formats against each other and returns the smaller one — sometimes that is WebP, sometimes JPEG.
- Convert PNG to WebP Convert PNG to WebP in your browser. Transparency is kept, and the tool measures whether the format change brings anything for your image at all.
By platform
- Optimize images for WordPress Scale images to 1600 px wide and compress them before they go into your WordPress media library — in your browser, with no plugin and no upload to a third party.
In preparation
These pages are not missing by accident. Each of them needs a platform figure that has to be documented — a pixel value from memory would make the tool factually wrong.
- Compress an image for email The independent fact here is the attachment limits of email providers. There is no single authority for them — every provider and every company gateway sets its own limit. Without documented sources, the page would remain a claim.
- Shopify: product image size The preset is documented. Beyond it, the page needs the specification in context — upper limits, the megapixel limit, what happens when an image deviates. Read first, then write.
- WooCommerce: product image size For WooCommerce, no fixed universal size is claimed: the target width comes from how the theme actually displays images. The page needs the shop image optimizer, and that needs verified theme and platform notes.
- Instagram: image size The preset carries 1440 px from the publishing API. Whether 1080 px applies to the app route is unverified — the value comes from this project’s specification, not from a retrieved source. Which number stands on a landing page is not a detail — it gets checked against the source.
- YouTube: thumbnail size The preset is documented. The page needs the requirement in context, including the two different file size limits for mobile and desktop.
- LinkedIn: banner size The independent fact is the safe zone — which area the profile photo and the mobile crop cover. The help page says nothing about it. A banner page without the safe zone would be half the answer.