About DropItOver

Browser File Transfer: Architecture and Privacy

DropItOver offers nearby browser transfers, live rooms, and temporary download links. Each mode has different networking, storage, and privacy requirements.

How DropItOver works

DropItOver is a browser file-transfer tool built in 2026. It offers nearby transfers, temporary links, and rooms because a shared Wi-Fi network, an offline recipient, and a group meeting need different paths. See the maintenance log for changes backed by repository history.

Nearby devices: discovery first, file transport second

Both browsers connect to a Cloudflare Durable Object over a WebSocket. The Worker hashes the public IP so devices sharing that address see a common peer list. It is not a LAN scan. VPNs, guest networks, and carrier NAT can change who appears. Confirm the device nickname before accepting a transfer.

Browser A ---- WebSocket signaling ---- Durable Object ---- Browser B
Browser A ===== SCTP over DTLS (direct or TURN relay) ===== Browser B

After acceptance, browsers exchange SDP and ICE candidates and open a WebRTC data channel. The sender applies backpressure above an 8 MiB channel buffer. The receiver assembles Blob parts, which still require resources proportional to the received file; a mobile browser can run out of memory. Neither browser may close the tab during a transfer.

Temporary links: server-managed encrypted storage

The sender uploads pieces over HTTPS. The Worker encrypts each piece with AES-256-GCM before storage in R2; file metadata and notes live in D1. The Worker controls the key, so this mode is not zero-knowledge. Files are limited to 2 GiB each and bundles to 8 GiB under the current defaults. Anonymous daily storage quotas apply.

Sender -- HTTPS -- Worker encrypts -- R2 ciphertext
Recipient -- HTTPS -- Worker decrypts -- R2 ciphertext

Choose an expiry from one hour to seven days. Expired links stop resolving; scheduled storage cleanup runs every ten minutes. A delete control or burn-after-read can remove a share earlier. These controls cannot revoke copies already downloaded by a recipient.

Rooms: an explicit invitation across networks

A room has a short identifier and supports up to eight browsers under the default configuration. Its WebSocket exchanges connection metadata, then participants send file payloads through WebRTC. TURN relay availability depends on server configuration and the networks involved. A room is not an access-controlled account workspace: protect its URL and confirm who joined.

Maintenance and support

Last reviewed: October 17, 2026. The 15 technical guides explain practical troubleshooting and document implementation limits. Performance examples label calculations separately from hardware measurements. The support form stores an inquiry and returns a ticket reference. Report the mode, browser, network arrangement, and reproducible steps without attaching private file contents.

Privacy boundaries

No account is needed for transfers. Connection metadata, temporary link data, support inquiries, and third-party advertising scripts still have privacy implications. Read the Privacy Policy for exact storage, retention, and advertising disclosures. A feature's presence here does not guarantee that every browser or managed network permits it.