Iterative quality search
Set a target size and the tool re-encodes at progressively lower quality until the file fits, so you get the best possible image under a hard limit.
Image Compressor
Reduce image file size without a visible drop in quality.
- Upload
- Batch upload supported · 25 MB max
- Privacy
- Nothing is uploaded
- Cost
- Free · no sign-up · no watermark
Loading tool…
The tool is loading its code on your device. This happens once and is cached for later visits.
Processed entirely on your device
Your file is read, transformed and re-encoded inside this browser tab using JavaScript. There is no upload endpoint — nothing leaves your machine, nothing is stored, and the result is created as a local object URL that disappears when you close the page.
Overview
About the Image Compressor
Compress JPG, PNG and WebP images by re-encoding at a target quality and optionally resizing. See the exact saving per file before you download.
Image compression is a negotiation between three things: how big the file is, how sharp it looks, and how large it is displayed. Most people only touch the first two and forget that dimensions dominate everything. A 4000×3000 photograph compressed to perfection still weighs more than a 1200×900 version at mediocre quality.
The order to work in
- Resize first. Match the image to its largest real display size. Retina screens want roughly double the CSS pixel width, so a 600-pixel column needs about 1200 pixels of image.
- Pick the right format. Photographs go to JPEG or WebP lossy. Logos, charts and screenshots go to PNG or WebP lossless.
- Then lower quality. Only after the dimensions and format are correct does the quality slider become the efficient lever.
Target-size mode
Some situations have a hard ceiling rather than a preference: a 500 KB portal upload, a 100 KB hero image for a performance budget, a 2 MB email attachment. Target-size mode handles this by binary-searching the quality parameter — encoding, measuring, adjusting — until the output fits under your number. It reports the quality it settled on so you can judge whether the result is acceptable.
What compression actually removes
JPEG and WebP lossy compression works in the frequency domain. It keeps the broad shapes and tones that your eye latches onto and discards fine high-frequency detail that it mostly ignores. That is why smooth skies survive brutal compression while hair, foliage and text fall apart — those are almost entirely high-frequency information.
If your image is mostly text or thin lines, do not use lossy compression at all. Keep it PNG, or resize it instead.
Verifying the result
Always compare at 100% zoom, not fit-to-screen. Browsers downscale previews in a way that hides exactly the artefacts compression introduces. The side-by-side preview in this tool renders both images at identical dimensions so the comparison is fair.
Step by step
How to use the Image Compressor
Add the images you want to shrink — several at once is fine.
Choose a target quality or set a maximum file size to aim for.
Optionally cap the width or height so huge photos are downscaled too.
Press Compress and watch the before/after sizes for each file.
Download the results, or adjust and re-run until the balance is right.
Why use it
Benefits and common use cases
What this tool is good for, and what it deliberately does not try to do.
Format-aware strategy
Photographs are compressed as JPEG or WebP; flat graphics are kept lossless where re-encoding would only add artefacts. You always see which path was taken.
Visible, measurable savings
Each result shows the original size, the new size and the percentage saved — no guessing whether the compression was worth it.
Meets real upload limits
Application portals, email attachments and CMS media libraries all impose caps. Target-size compression is built to hit them exactly.
Questions
Frequently asked questions
Short, honest answers about quality, limits and privacy.
How much can I compress an image before it looks bad?
For photographs, quality 70–85% is usually indistinguishable on screen. Below 60% you will start to see blocking in gradients and smearing around sharp edges. Resizing gives far bigger savings than dropping quality, so reduce dimensions first.
Can I compress a PNG without losing transparency?
Yes, if you keep it lossless — but lossless PNG compression only removes redundant encoding, typically saving 10–30%. For large savings on a transparent image, convert to WebP, which keeps the alpha channel and compresses far better.
Why did my image get bigger after compression?
It happens when a small, flat graphic is re-encoded as JPEG or when a heavily-compressed source is re-encoded at higher quality. The tool warns you when the output exceeds the input and lets you keep the original instead.
Does resizing reduce quality?
Downscaling discards pixels, so fine detail is lost — but the result is still sharper than a full-size image squashed to the same file size. Always downscale to the largest size you actually display.
Is there a limit on how many images I can compress?
You can add up to 20 files per batch with no account and no daily cap. Because processing is local, the only real constraint is your device's available memory.