Sukat · Offline-capable

An image compressor that runs without internet

Offline image compression — Sukat loads once, then runs entirely client-side. Airplane mode, flaky cafe Wi-Fi, fully firewalled corporate networks, remote-site work: the tool just keeps working because there’s nothing to call home to. Drop the image, set a KB ceiling, download — signal bars optional.

Open Sukat now →
Last reviewed: May 2026
An image compressor that keeps working in airplane mode Animation: a stylised airplane-mode badge pulses in the top-left while a clear “no network” indicator is lit. The file-size readout still counts down through a binary search and lands at 96 KB, under the user’s ceiling. A “verified offline” badge appears at the DONE state. AIRPLANE MODE Sukat keeps working NO NETWORK 0 server calls · 0 uploads YOUR LIMIT your KB ← no network needed CURRENT FILE SIZE 3.8 MB 1.1 MB 380 KB 142 KB 96 KB binary search · runs entirely in the browser VERIFIED OFFLINE 96 KB — saved locally no upload · no server pass
How to

Compress images with no internet

Three steps. Load the page once on any connection, then disconnect — the compressor keeps running.

Load the page once

Open sukatapp.com on any connection. The HTML, scripts, HEIC decoder, AVIF decoder, and ZIP packager all cache locally during this first load. Nothing else is fetched after that for normal compression.

Go offline — or stay online, your call

Switch to airplane mode, walk into a tunnel, or stay on Wi-Fi. Sukat behaves identically either way. The only network call in the entire app is a decorative global counter that fails silently without affecting your conversion.

Drop, target, download

Drop a JPG, PNG, WebP, HEIC, AVIF, or GIF. Type a KB or MB ceiling. Click Convert & Download. The binary search runs through the Canvas API in your browser and saves the result locally — no round-trip.

When you need it

When “no internet” is the constraint

Most “free online image compressors” are a thin wrapper over an upload + server-side process. Kill the connection and they die. Here is where that fails the user.

  • In-flight photo editing. Long-haul flights with satellite-only Wi-Fi that’s metered to the gigabyte, or no Wi-Fi at all. Tidy up the shots taken during boarding so they’re ready to send the second the plane lands.
  • Remote-site work. Research expeditions, oil rigs, ships at sea, mountain weather stations — anywhere the connection is satellite, intermittent, or technically nonexistent. The tool just runs.
  • Developing-market connectivity. On a metered mobile plan, a 4 MB upload is a noticeable bite. Compressing locally before sending shifts the burden off the data cap entirely.
  • Firewalled enterprise networks. Many corporate networks block upload-based image tools as a data-exfiltration risk. A page that runs locally has nothing for the firewall to inspect, so it passes through.
  • Airport and hotel Wi-Fi. Captive portals that allow basic browsing but throttle or block file uploads. Slow, often insecure, and the wrong place to send anything sensitive in the first place.
  • Travel photographers needing PWA-like reliability. Add Sukat to the home screen and it opens like a native app, available in airplane mode for the entire trip — no app-store install, no account.
Why Sukat

Genuinely offline, not “offline-ish”

Plenty of compressors claim “works offline” and quietly fall over the moment the upload step needs a server. Sukat’s architecture removes that step entirely.

100% client-side from day one

There is no Sukat compression server. The binary-search-to-target-size logic, the HEIC and AVIF decoders, the live quality preview, the ZIP packager — all of it ships with the page and executes through the Canvas API in your browser. The architecture is the feature.

Loads once, then no network needed

The entire app is a static bundle delivered from Cloudflare’s edge. After the first load, the browser caches it like any other website. You can refresh the tab in airplane mode and the page still opens.

Verifiable in airplane mode

Don’t take the marketing at face value. Open Sukat, switch to airplane mode, then drop an image — it still compresses. Or open DevTools ’ Network tab while online and watch: no upload request is ever made.

No PWA install required — but supported

The page works offline as a normal browser tab — just bookmark it. For one-tap launching, tap Share › Add to Home Screen on iOS, or the menu › Install app on Android. Either way, no app-store account, no native install.

HEIC, AVIF, GIF all decode locally

The decoders for modern image formats are bundled with the page, not loaded on demand. iPhone HEIC photos, AVIF screenshots, and animated GIFs all open in airplane mode without any “converting…” spinner that turns out to be a hidden server call.

Batch and ZIP still work offline

Drop a dozen photos at once, set a target, and the batch runs locally with a single ZIP at the end. The ZIP packager is bundled too — there’s no “preparing your download” server stage.

Live preview still works offline

The quality slider previews the output in real time, also entirely in the browser. There’s no re-fetch from a server every time the slider moves — the preview is just another Canvas render.

Questions

FAQ

Does Sukat really work without internet?

Yes. Once the page has loaded, the entire compression pipeline runs in your browser. Verify it the simple way: load Sukat on Wi-Fi, switch to airplane mode, then drop an image — it still compresses, crops, and downloads. The only network call in the app is a decorative global counter that fails silently when offline without affecting the conversion.

Do I need to do anything special to cache the page?

No. Modern browsers cache static pages and assets by default, so the first visit is enough to make the site usable offline in the same browser session. For longer offline reliability across tab closes and device restarts, leave the tab open or use Add to Home Screen.

Is there a PWA install I should use?

The page works offline without it — a normal bookmark or open tab is enough. If you want one-tap launching from the home screen, tap Share › Add to Home Screen on iOS or the browser menu › Install app on Android. There’s no app-store install and no account anywhere in the flow.

How big a batch can I run offline?

As big as your device’s RAM and CPU comfortably handle. There’s no server-side queue limit because there’s no server. On a modern laptop, batches of 50–100 photos under 5 MB each typically run without issue. On a phone, expect 10–30 depending on resolution and free memory.

Can I share the cached page with someone else?

Not directly — each device caches its own copy through its own browser. The fix is the same trivial step: share the URL sukatapp.com and have them open it once on any connection. After that, their browser handles caching automatically and they can disconnect.

Does analytics still run when I’m offline?

No, and that’s by design. The decorative global conversion counter is the only network call — it sends just a “+1” with no image data — and it fails silently when offline. Your conversions complete normally and nothing about them gets recorded server-side.

Drop the image. No signal required.

Free, browser-based, no upload, no watermark. Works on a plane, in a tunnel, behind a corporate firewall.

Open Sukat now →