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    ZIP Preview

    Inspect what is inside a ZIP file — names, sizes, and compression ratios — without extracting it. Free, fast, and processed entirely in your browser.

    • Runs in your browser
    • No uploads
    • Works offline
    • Unlimited & free

    Loading ZIP Preview…

    Why use this tool

    What you get here that a server-side alternative cannot offer.

    • Your data never leaves the tab

      There is no upload step and no server to receive one. The page loads once, then all work on your archives happens in local JavaScript.

    • No upload or queue wait

      Processing starts the moment you press the button. You are not waiting on a network round-trip or a shared job queue, so results are effectively instant.

    • No caps or paywalls

      No daily limits, no per-file ceilings imposed by a server tier, no watermarks, and no account. The practical limit is your own device's memory.

    • Keeps working offline

      Once the page has loaded you can go offline and it still works, because the code that does the job is already on your machine.

    • Safe for confidential files

      Contracts, invoices, medical scans, and internal documents can be processed without them ever being transmitted — which is often the difference between being allowed to use a tool at work and not.

    How it works

    1. Step 1: Choose your ZIP file

      Pick a file from your device or drag it onto the page. It is read locally — the file is never transmitted.

    2. Step 2: Inspect the contents

      Set the options you want and run it. Progress is shown as your browser works through the file.

    3. Step 3: Download the result

      Save the finished file straight back to your device. Nothing is retained after you close the tab.

    Frequently asked questions

    No. Everything runs locally in your browser using JavaScript — your data is never uploaded to a server, and nothing is stored or logged.

    To spot archives that dump dozens of files into your current folder, and to confirm the download contains what you expect before committing disk space to it.

    Each entry's path, original size, compressed size, and the resulting ratio, so you can see the directory structure at a glance.

    There is no limit imposed by us, because there is no server tier to enforce one. The real constraint is your device's available memory, since the whole file is held in RAM while it is processed. Very large files are slower on phones than on a laptop.

    Yes, once the page has loaded. The code that does the work is already in your browser at that point, so you can disconnect and keep using it. Reloading the page while offline needs the browser cache to still hold it.

    No. There is no sign-up, no email, and no usage tracking tied to an identity. The tool works the first time you open it.

    Explore more browser-first tools

    Every tool on ToolOcean runs the same way this one does — the work happens in your tab, and your files stay on your machine.

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