How it works

From drop to

One flow from the first file you drop to the receipt at the end. Here is exactly what happens along the way

The flow

Four steps,

  1. 01

    Drop

    Open Clex and drag files in, paste them, or pick them. They are held in your browser's memory. Nothing is uploaded to any server.

    • Drag and drop
    • Click to browse
    • Paste
  2. 02

    Prepare

    Compress images, merge or split PDFs, convert Word files to PDF and bundle everything into a ZIP. When one tool finishes, Clex suggests the next.

    • Compress
    • Merge
    • Convert
    • ZIP
  3. 03

    Share

    Clex creates a six character room code, a link and a QR. A small signaling server introduces the two browsers, then steps aside and the data channel opens between them.

    • Direct
    • Local network
  4. 04

    Verify

    Direct+ sends 64 KB chunks with up to 8 MB in flight. The receiver acknowledges each one, lost chunks are resent and damaged ones re-requested by hash. At the end both sides build a receipt that holds no file content.

    • Chunk ACK
    • Pause and resume
    • Receipt
Direct+ on the wire

How a transfer

Five stages between two browsers. Older Clex peers skip the first and fall back to the plain transfer automatically

  1. 1
    Capability handshake

    Both sides announce what they support. If either lacks Direct+, they agree on the classic protocol instead.

  2. 2
    Manifest

    The sender lists every file, its size and, within the hashing budget, a SHA-256 for each chunk.

  3. 3
    Chunks in a sliding window

    64 KB frames stream with up to 8 MB in flight. The receiver acknowledges each one as it lands.

  4. 4
    Verify and retry

    Sizes and hashes are checked on arrival. Anything missing or damaged is asked for again, and only that.

  5. 5
    Receipt

    Both peers build the same content free summary: file count, size, chunks, retries, route and a root hash.

Read the developer reference
Vault

Private work has

Vault runs beside transfers in the same workspace. Notes stay local, and secret links carry their own rules

01

Write locally

Notes are encrypted in the browser, organised into folders and available offline. Your device holds the primary copy, and paired devices sync peer to peer.

02

Choose the protections

Secret links let you pick an expiry and switch on view once, a 60 second viewing window, no select, a tab switch lock or a DevTools guard.

What if

The edge cases,

The things that go wrong on real networks and real devices, and what Clex does about each one

I'm offline

After Clex loads once, the preparation tools keep working with no connection. Compress, merge and convert, then share when you are back.

The file is huge

Transfers stream chunk by chunk and are never loaded whole, so size is limited by your browser, not by Clex. For very large files between nearby devices, use the local route.

The browsers can't connect

Some strict networks block direct connections. Clex tells you plainly rather than falling back to uploading your file. Try the local route if you share a network.

Which browsers work

Any modern browser with WebRTC: Chrome, Safari, Firefox and Edge, on desktop and on mobile. Nothing to install on either side.