Image Compressor
Make photos and graphics smaller — or fit them under a KB limit — without uploading.
Settings
Keeps the aspect ratio. Smaller images are not enlarged.
Metadata can include the camera, the date and the GPS location where the photo was taken. Leave this off to remove it.
Your images
Compare
Use Actual pixels to inspect fine detail at 100% — both sides scroll together.
About the Image Compressor
Make images smaller without sending them anywhere. Drop in JPG, PNG or WebP files and they are re-encoded in your browser: photos at the quality you choose, PNG graphics either by reducing the number of colours (the technique popular PNG optimisers use) or by lossless re-packing. Every file shows its size before and after, and you can compare the result with the original side by side — at 100% if you like — before downloading.
Need a file under a limit, such as a 50 KB photo for an exam, job or government application form? Turn on Fit under a file size and the compressor searches for the highest quality that fits, reducing the dimensions only when it has to.
How to use it
- Drop images onto the box, click Choose images, or paste a screenshot with Ctrl/⌘ + V. You can add up to 100 at a time.
- Keep Same as original to compress without changing the format, or pick JPG, PNG or WebP. Adjust Quality (JPG/WebP) or Colours (PNG) — results update automatically.
- Optional: turn on Resize large images to set a maximum width or height, or Fit under a file size to hit a target in KB.
- Check the saving on each file, use the eye button to compare, then download images one by one or Download all as a ZIP.
Examples
Fit under a file size: 50 KB · Allow smaller dimensions: on
A JPG of at most 50,000 bytes at the highest quality that fits; the list shows the quality used and any change in dimensions.
If the form also requires exact pixel dimensions (for example 200 × 230 px), set them first with the Image Resizer.
4032 × 3024 JPG · Resize large images: max width 1920 · Quality 80
1920 × 1440 JPG — about a quarter of the pixels, so typically a fraction of the original size.
PNG · Lossy · 256 colours · Dithering on
An 8-bit palette PNG that keeps transparency; screenshots and flat graphics usually shrink a lot with no visible change.
Common uses
- Getting photos and scanned signatures under the KB limits of exam, job and government application forms.
- Making web pages load faster: smaller images download sooner, especially on mobile data.
- Emailing or messaging many photos without hitting attachment limits.
- Shrinking PNG screenshots and UI graphics for documentation, tickets and chat.
- Removing camera details and GPS location from photos before sharing them.
How each format is compressed
- JPG and WebP are lossy: the encoder discards detail the eye notices least. Lower quality means smaller files and more visible artefacts (blockiness, smudged fine detail). Start at 80 for photos and compare at 100%; if you cannot see a difference, try lower.
- PNG (Lossy) reduces the image to at most the number of colours you choose (2–256) and saves it as an 8-bit palette PNG, keeping transparency. Dithering mixes neighbouring colours to hide banding in gradients.
- PNG (Lossless) keeps the image looking exactly the same and re-packs the file: a palette when there are 256 colours or fewer, greyscale or RGB without an alpha channel when possible, the best row filter for each line and maximum compression. Opaque pixels are stored exactly; partly transparent pixels can shift by a rounding step, because browsers keep canvas pixels premultiplied by their transparency.
- WebP is often the smallest choice. Google reports that lossy WebP files are 25–34% smaller than comparable JPEGs at equivalent SSIM quality, and lossless WebP files 26% smaller than PNGs (WebP documentation).
How “Fit under a file size” works
The compressor encodes the image several times, searching (by halving the range each time) for the highest quality — from your quality setting down — whose file is at or below the target. For PNG it searches the number of colours instead. With Allow smaller dimensions on, it does not go below quality 40 (or 64 colours), because lower settings look visibly damaged: if that is still too big, it scales the image down step by step until it fits. With the option off, it goes as low as quality 5 (or 2 colours) and keeps the dimensions.
The target is for the whole file: with Keep photo metadata on, the metadata counts towards it and the picture gets the rest. If the metadata leaves too little room for the picture, the list says so. The target uses 1 KB = 1,000 bytes, so the file also passes upload checks that count 1 KB as 1,024 bytes.
Metadata and privacy
Re-encoding an image in the browser removes its metadata: camera model, date taken, GPS location and other EXIF fields are not copied to the compressed file. If you want to keep them (for example so photo apps still sort by date), turn on Keep photo metadata — this applies to JPG to JPG compression, resets the orientation tag and removes the embedded thumbnail.
When Keep the original if it is already smaller hands back your original file, its metadata is still removed — without re-encoding, so the picture itself is untouched — unless you turned on Keep photo metadata. Colour profiles stay so colours look the same, and a photo taken sideways keeps only its rotation flag so it still displays upright.
Limitations
- Images up to 50 megapixels and 200 MB each, up to 100 images per batch. Large images can take a few seconds each on phones.
- Animated GIF, PNG and WebP files keep only their first frame.
- Colours are converted to standard sRGB by the browser, so wide-gamut (Display P3) photos can lose a little saturation. PNG files with 16 bits per channel are saved with 8 bits per channel, the precision browsers decode them at.
- Results depend on your browser’s built-in JPG/WebP encoders: the same quality number can give noticeably different file sizes in Chrome, Firefox and Safari (Safari’s scale is different). AVIF output appears only if your browser can create AVIF files.
- Lossy compression cannot be undone — keep your original files.
Privacy
Images are processed in your browser and are never uploaded. The files you download contain no camera details, dates or GPS location unless you choose to keep the photo metadata.
Frequently asked questions
Are my images uploaded to a server?
No. Compression runs entirely in your browser, using its built-in image encoders plus MySmartCoPilot’s PNG and WebP encoders, which are part of the page. Once the page has loaded it keeps working without an internet connection.
What quality setting should I use?
For photos, 75–85 is a good starting point. Compare the result at 100% (Actual pixels): if it looks the same as the original, try a lower value. For images with text or sharp edges, use PNG or a higher quality.
How do I compress an image to 50 KB or 20 KB?
Turn on Fit under a file size, type 50 (or 20) and keep Allow smaller dimensions switched on. The tool finds the highest quality that fits and, if needed, reduces the pixel size. If the form also specifies dimensions, set them first with the Image Resizer.
Why did one of my files get bigger?
Images that are already well compressed — or saved at a lower quality than your setting — can grow when re-encoded. With Keep the original if it is already smaller on, you get your original file back in that case and the list says so.
Will PNG colour reduction make my image look worse?
Screenshots, logos and illustrations usually look identical at 256 colours. Photos and smooth gradients can show banding; Dithering hides most of it. If you need every colour, choose Lossless — or convert photos to JPG or WebP, which suit them better.
Does compressing remove the location from my photos?
Yes. Unless you turn on Keep photo metadata, the files you download contain no EXIF, XMP or IPTC metadata — no GPS coordinates, camera details or dates — even when your original is handed back because it was already smaller.