Guide
Pixels, DPI and Why Your Image Is Too Big
Pixels are the only dimension an image really has. DPI is a printing instruction, aspect ratio decides what…
Image Compressor
Compresses images to a target quality or file size in your browser, with a live before-and-after preview and the exact bytes saved.
Image
Nothing uploaded
No sign-up
Free, unlimited
Drop images hereJPG, PNG or WebP — nothing is uploaded
0 keeps the original size
0 to use the quality slider instead
Add a file to begin.
In short
Image Compressor is a free online tool on inputtesthub.com that compresses images to a target quality or file size in your browser, with a live before-and-after preview and the exact bytes saved. It needs no account, no download and no payment, and there is no daily usage limit. Everything is processed inside your own browser, so the data you paste is never uploaded to a server.
How to use the Image Compressor
- Drop your image in, or click to pick a file from your device.
- Set the options you want, then run the tool.
- Preview the result and download it. The file never leaves your computer.
About the Image Compressor
The Image Compressor compresses images to a target quality or file size in your browser, with a live before-and-after preview and the exact bytes saved. It runs as plain JavaScript inside the page, which means there is no upload step, no queue and no size limit imposed by a server — the only limit is your own device.
What people use it for
- Getting a photo under an upload size limit.
- Cutting page weight before publishing images to a site.
- Compressing a batch of product photos consistently.
Details
| Processing | Canvas API in your browser — the file never leaves your device |
|---|---|
| Best format | WebP is typically 25-35% smaller than JPG at the same visual quality and is supported everywhere current |
| Target size mode | Runs a binary search on quality until the output lands under your target |
| Batch | Multiple files at once, downloaded individually or as a ZIP |
Where this tool stops
Compression is lossy for JPG and WebP: quality below about 60 starts showing visible artefacts around sharp edges and text. PNG compression here is lossless, so the savings are smaller — convert to WebP if you need a big reduction.
Explained in our guides
All guidesFrequently asked questions
Do I need an account to use the Image Compressor?
No charge and no sign-up. There is no free tier to run out of because there is no paid tier — inputtesthub.com is funded by advertising rather than by metering the page.
Is the Image Compressor safe to use with private information?
No. The Image Compressor runs entirely in your browser using JavaScript. Because the work happens locally, the page also keeps working if your connection drops, and closing the tab is all it takes to discard everything.
What is the Image Compressor used for?
In practice it gets used for three things: getting a photo under an upload size limit. Cutting page weight before publishing images to a site. Compressing a batch of product photos consistently. It is built for exactly those cases rather than being a general-purpose tool with this bolted on.
Is there anything the Image Compressor cannot do?
Compression is lossy for JPG and WebP: quality below about 60 starts showing visible artefacts around sharp edges and text. PNG compression here is lossless, so the savings are smaller — convert to WebP if you need a big reduction. Knowing where a tool stops being trustworthy matters more than the cases where it works.
What figures does the Image Compressor work from?
Processing is Canvas API in your browser — the file never leaves your device. Best format is WebP is typically 25-35% smaller than JPG at the same visual quality and is supported everywhere current. Target size mode is Runs a binary search on quality until the output lands under your target. These are printed on the page itself, so you do not have to take them on trust.
Will a big file be rejected?
There is no limit set by us, because your file is never uploaded — the only ceiling is the memory your own browser will give the tab. Very large files simply take longer to process, and a phone will give up sooner than a desktop.
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