About JpegDiet

JpegDiet is a free online image compressor with one defining principle: your images should never leave your device. Every resize, format conversion and compression step runs locally in your browser using standard web APIs. There is no upload, no server-side processing, and no storage of your files anywhere.

Why we built it

Most online compressors ask you to upload photos to their servers. That's a reasonable trade for some use cases, but it's the wrong trade for passport scans, ID photos, contracts, or anything private. We wanted a compressor that a cautious person could use for sensitive documents with full confidence — so we built one where the sensitive part literally cannot be transmitted, because the code that does the work has no upload path in it.

We also wanted precision. Forms and portals impose hard limits like "maximum 100 KB", and eyeballing a quality slider rarely lands under them. JpegDiet takes a target file size and guarantees the output fits, by automatically finding the highest quality that fits the budget.

How it works

Under the hood the tool uses the HTML5 Canvas API. Your image is decoded into a canvas, then re-encoded as JPG or WebP at a series of quality levels while a binary search narrows in on the largest quality that still fits your target size. If the target is unreachable through quality alone, the image is progressively scaled down. Nothing in this pipeline touches the network.

How the site is supported

JpegDiet is free with no sign-up and no watermark. The site is supported by display advertising, which pays for the domain and hosting. Ads never see your images — only standard, anonymous ad delivery described in our Privacy Policy.

Get in touch

Found a bug, have a format request, or want a feature added? We read everything — see the contact page.