Image compressor
Compress, convert and resize images without uploading them anywhere.
Runs entirely in your browser. Nothing you paste is uploaded or stored.
The useful range — visually identical for photographs.
Images are never enlarged — a picture narrower than the limit is left at its own size.
Processed images appear here with the size before and after.
Nothing is uploaded: the files are decoded and re-encoded by your own browser. As a side effect all metadata is stripped, including GPS coordinates from phone photos.
What this tool does
It compresses, converts and resizes images entirely inside your browser. Drop in a batch, pick a format and a width, and get every file back with the before and after size next to it.
The privacy part is not a marketing line, it is the architecture. There is no upload step because there is nowhere to upload to — the page has no server behind it doing work. For anyone handling client screenshots, unreleased product photos or anything covered by an NDA, that difference matters more than a few kilobytes.
Choosing a format
WebP is the safe default. Every current browser supports it, and it is typically 25 to 35 percent smaller than an equivalent JPEG.
AVIF goes further — usually another 20 to 30 percent below WebP — at the cost of slower encoding. Use it when you can serve a <picture> element with a WebP fallback.
JPEG remains right for photographs when compatibility with very old software matters. Note that converting a transparent PNG to JPEG flattens transparency onto white, because JPEG has no alpha channel.
PNG is lossless and belongs to screenshots, diagrams, logos and anything with text or flat colour. Compressing those as JPEG produces the halo artefacts around letters that make a page look cheap.
Resizing is where the real saving is
Quality settings shave percentages. Dimensions change the arithmetic entirely: a 4000 pixel wide photo displayed in an 800 pixel column carries twenty-five times more pixels than the layout can show. Resizing to the width you actually use will usually save more than any codec choice, and it costs nothing visually.
The common widths are here as presets: 1200 pixels for an in-article image, 1920 for a full-width header, 600 for a thumbnail. Images narrower than the limit are left alone rather than being scaled up.
Questions
Are my images uploaded to a server?
No, and this is the main reason to use it. The images are decoded and re-encoded by your own browser using canvas, so nothing is transmitted. Every competing tool of this kind uploads your file, processes it on their machine and asks you to trust their retention policy.
What happens to EXIF and location data?
It is removed, because re-encoding through canvas keeps only the pixels. That is worth knowing in both directions: a phone photo published to a website no longer carries the GPS coordinates of where it was taken, and a photo you needed the camera data for will lose it.
WebP or AVIF?
AVIF is usually 20 to 30 percent smaller than WebP at the same visual quality and takes noticeably longer to encode. Both are supported by every current browser. If you serve a single format with no fallback, WebP is the safer default; if you can serve a picture element with fallbacks, AVIF first.
Why did my file get bigger?
Because it was already compressed harder than the quality you selected. Re-encoding an image that is already small at quality 90 produces a larger file, not a smaller one. Lower the quality or keep the original for those files.
What quality should I use?
Between 70 and 85 for photographs — the difference from the original is invisible at normal viewing size and the saving is large. Screenshots and images containing text are the exception: flat colour and sharp edges show artefacts early, so keep those higher or use PNG.