About the Image Compressor
Zyff's image compressor shrinks PNG, JPG, WebP and AVIF files so pages load faster and uploads stop getting rejected. Pick an output format, set the quality, and see the exact byte count and percentage you saved before you download anything. Compression runs on Zyff's servers with sharp and mozjpeg, in memory only, so your file is never stored. Free and unlimited, with no signup and no watermark.
How to compress an image online
Upload your image
Drop a JPG, PNG, WebP, AVIF, TIFF or SVG file onto the upload zone, or click to browse. Anything up to 25 MB per image is accepted.
Choose an output format
WebP is the default and the safest all-round pick for the web. Choose AVIF for the smallest file, JPEG for maximum compatibility, or PNG for lossless output.
Set the quality
Drag the quality slider between 10 and 100, leaving it near 80 for photographs. The slider is disabled for PNG because PNG output is always lossless here.
Compress and compare
Click Compress image, then open the Before / after tab and drag the slider to inspect the result against the original. A badge shows how much smaller it got.
Download or copy
Download the compressed file, which keeps your original filename with the new extension, or copy it straight to the clipboard to paste somewhere else.
What the Image Compressor does
Four modern encoders
Encode to WebP, JPEG, PNG or AVIF from a JPG, PNG, WebP, AVIF, TIFF, GIF or SVG source, all from one control instead of a separate converter.
Genuinely lossless PNG
PNG output keeps every pixel at maximum zlib compression with no palette quantization, which is why the quality slider switches off instead of quietly changing your pixels.
mozjpeg for JPEG output
JPEG is encoded with mozjpeg and written progressive, so it comes out smaller than a standard encoder at the same quality and paints top-down on slow connections.
Before and after slider
Drag the compare slider to check the compressed result against the original at full size, with both byte counts and the exact savings shown on screen.
One-click downscale
Check Resize to max 1600px to cap the longest edge. On a camera photo that is usually a bigger saving than anything the quality slider can do on its own.
Metadata stripped
Re-encoding drops EXIF and GPS data after baking in orientation, so a portrait photo stays upright and nothing personal travels with the file you share.
At a glance
| Input formats | JPG, PNG, WebP, AVIF, TIFF, SVG, GIF (first frame) |
|---|---|
| Output formats | WebP, JPEG, PNG (lossless), AVIF |
| Max file size | 25 MB per image |
| Quality range | 10-100, disabled for PNG output |
| Optional downscale | Longest edge capped at 1600 px |
| Price | Free and unlimited, no signup |
| Watermark | None |
Frequently asked questions
How do I compress an image without losing quality?
Choose PNG output for genuinely lossless compression, or keep the quality slider at 80 or above for JPEG, WebP and AVIF. At 80 the difference is very hard to see on a photograph, and the Before / after tab lets you compare the two at full size before you commit to the download.
What quality setting should I use for JPEG, WebP or AVIF?
Use 80 for photographs, 60 to 70 for large background images, and 90 or above for screenshots and flat graphics with hard edges. Quality trades detail for bytes in all three formats: as the number falls, smooth gradients start to band and hard edges pick up ringing. The scale is not comparable between codecs, so switching format often saves more than dragging the slider down. The scale is not comparable between codecs, so switching format often beats dragging the slider down.
Does compressing a PNG lose quality?
No. PNG output is written at maximum zlib compression with no color reduction, so every pixel comes back identical to the source. That is why the quality slider is disabled for PNG: sharp's PNG quality, effort and colors options each turn on palette quantization, which would silently change your image.
What is the best format to compress images for the web?
WebP is the default because every current browser supports it and it handles photographs and flat graphics equally well. AVIF usually produces the smallest file at the same quality setting, JPEG is the safest choice for older software and email, and PNG is for lossless output or transparency.
How do I reduce an image to a specific file size, like under 100 KB?
Compress once at the defaults and read the exact output size in the results row, then adjust and re-compress. Dropping the quality to 60-70 and turning on Resize to max 1600px are the two biggest levers, because pixel count drives file size even more than the quality dial does.
What is the largest image I can compress?
Uploads are capped at 25 MB per image, and the limit is enforced on the server as well as in the upload zone. The compressor works on one image at a time; if you need to process many files in one go, Zyff's format converter queues up to 25 and returns them as a ZIP.
Does Zyff store the images I upload?
No. The bytes you send exist as a buffer for one HTTP request and go out with it — nothing is written to disk, nothing is queued, and the response carries a no-store header so it is not cached on the way back either. Zyff has no accounts, so there is no list of past files anywhere to worry about.
Can I compress images on an iPhone or Android phone?
Yes. The workbench is built mobile-first and works down to a 320px screen, with the settings panel stacked under the preview. Encoding happens on Zyff's servers, so a phone gets exactly the same output as a desktop. For HEIC photos straight off an iPhone, start with Zyff's format converter.
How do I compress an image to email it?
Choose JPEG at quality 75 to 80 and tick Resize to max 1600px, which brings almost any phone photo well under the per-message limit mail providers enforce. Gmail and Outlook cap a whole message at roughly 20-25 MB, so if you are attaching several photos, add up the compressed sizes shown in the results row. JPEG is the safest format for mail because every client and mobile preview opens it.