Sukat · Browser-based

Image compression that never leaves your browser

Browser-based image compression in the literal sense — the file never leaves your device, the algorithm runs on the Canvas API your browser already ships with, and the network is verifiable in airplane mode. Sukat is the constraint-driven compressor that respects this contract by design.

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Last reviewed: May 2026
A browser window compressing an image locally without any upload Animation: a stylized browser window at sukatapp.com binary-searches a 3.8 MB image down through 1.1 MB, 380 KB, and 142 KB, landing at 96 KB. A NO UPLOAD badge confirms the file never left the device. sukatapp.com YOUR LIMIT your KB no upload ever ← the ceiling Sukat must stay under CURRENT FILE SIZE 3.8 MB 1.1 MB 380 KB 142 KB 96 KB canvas API · binary search runs entirely in this browser tab DONE 96 KB — fully local NO UPLOAD network was never touched
How to

Compress images in the browser

Three steps. The compression code executes inside your browser’s JavaScript engine on your own device — verify it yourself in DevTools or airplane mode.

Open Sukat in any browser

Visit sukatapp.com in Chrome, Safari, Firefox, or Edge — desktop or mobile. No installer, no account, no email confirmation. The full app loads as a static page.

Verify it’s client-side (optional)

Open DevTools (right-click → Inspect, then the Network tab) before dropping a file. Drop and convert. No image upload appears. Or simpler: switch to airplane mode after the page loads — compression still works.

Drop, target, download

Drop your image, type a KB or MB ceiling, pick the output format, click Convert & Download. The file never leaves your device. Even the download is a local blob, not a server-issued link.

When you need it

When “browser-based” is a hard requirement

Most “free online image compressor” tools quietly POST your file to a remote server. For the workflows below, that’s a non-starter.

  • Privacy-conscious freelancers handling client photos, brand assets, or unreleased product shots that can’t legally or ethically sit on a third-party server even briefly.
  • Legal and healthcare professionals compressing exhibits, ID scans, or radiology stills — client confidentiality and HIPAA-style obligations make any third-party upload a liability event.
  • Corporate environments where IT blocks file-upload domains as a DLP policy. Browser-based compression has nothing to upload, so the policy never trips.
  • Firewalled networks behind a corporate proxy, government intranet, or school filter that strips outbound multipart POSTs to unknown hosts.
  • Airplane Wi-Fi and metered connections where uploading a 4 MB original to compress it down to 100 KB is the opposite of what bandwidth-constrained users want.
  • Anyone wary of cloud compressors silently storing files for training data, ad targeting, or “quality improvement” — if there’s no upload, there’s nothing to store.
Why Sukat

Browser-based the whole way down

Plenty of tools say “online” and mean upload. Sukat says browser-based and means it — the entire pipeline is in your tab.

100% client-side via the Canvas API

JPEG and WebP encoding runs through HTMLCanvasElement.toBlob(), the same primitive your browser already uses to render every photo on the web. PNG output, ICO packaging, even the binary-search loop around quality — all of it executes inside the JavaScript engine on your CPU. No server is contacted for the compression step.

No upload, no signup, no watermark

Sukat is hosted as a static site on Cloudflare Workers Assets. There is no backend to authenticate against, no account database, no rate limiter. You don’t get a watermark above five photos because there is no “above five photos” tier.

Offline-capable — works once loaded

After the first page load, Sukat runs without network access. Airplane mode, hotel Wi-Fi captive portals, tunnels, planes — the tool keeps compressing because nothing is fetched mid-conversion. See Offline Image Compressor for the full breakdown.

Zero server cost equals zero incentive to monetise your files

Server-side compressors pay for every uploaded megabyte. That cost has to come from somewhere — usually ads, watermarks, training-data licensing, or affiliate funnels. Sukat’s server cost is the static-asset bandwidth and nothing else, which removes the structural incentive to do anything with your images at all.

HEIC and AVIF decoded in-browser

Many browser-based compressors reject HEIC because their stack doesn’t include a decoder. Sukat ships heic2any (libheif compiled to WebAssembly) for HEIC and uses the browser’s own AVIF decoder — both run locally, no “upload to convert” detour.

Multilingual UI plus a live quality preview

The interface ships in 10 languages including Hindi, Spanish, Portuguese, Arabic, Filipino, and Indonesian — most browser-based compressors are English-only. The live quality preview slider, which Squoosh has and almost nobody else does, lets you trade quality for size before committing.

Questions

FAQ

How can I verify Sukat is genuinely browser-based?

Two ways. Airplane mode: open the page on Wi-Fi, then disconnect entirely. The compressor keeps working because nothing is uploaded during conversion. DevTools: right-click → Inspect, open the Network tab, drop an image, and watch — no multipart POST appears with your image bytes. The only network calls during the page session are font and asset fetches that already happened at load.

What about big files? Can the Canvas API really handle multi-MB images?

Yes. The Canvas 2D context handles photos in the tens of megapixels routinely — a 24-megapixel DSLR shot or a 12-megapixel iPhone HEIC decodes and re-encodes in well under a second on a modern device. For very large source files (over 50 MB or so), Sukat downscales dimensions internally before the encoding pass so the canvas stays within the browser’s per-tab memory budget.

Does Sukat support iPhone HEIC photos in the browser?

Yes. Sukat bundles heic2any, a JavaScript port of libheif compiled to WebAssembly, which decodes HEIC to a Canvas-ready bitmap entirely inside your tab. No server conversion step, no “upload to convert” detour — you can drop a raw iPhone HEIC straight onto the drop zone.

Can I batch-compress multiple images in the browser?

Yes. Drop several files at once and Sukat processes each one independently in your tab, then bundles the results into a single ZIP via JSZip — also a pure-JavaScript implementation, also browser-side. Nothing is uploaded; the ZIP is built in memory and offered as a local download.

What’s the practical difference from upload-based compressors?

An upload-based compressor sends your file to a remote server, runs ImageMagick or libvips there, and returns the compressed result as a download. That means your image sits on a third-party machine for the duration of the request (and possibly longer, depending on retention policy). Browser-based compression skips all of that — the same encoding work happens locally, usually faster, with the file never leaving your device.

Does Sukat run analytics or tracking on my images?

Sukat does not read, sample, hash, or transmit the content of your images. The site uses minimal anonymous page-load analytics for traffic counts — that ping carries no image data and is unrelated to the compression pipeline. The encoding code path has no network calls at all.

Your tab. Your CPU. No upload.

Free, browser-based, no signup, no watermark. Verify it in airplane mode if you like.

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