Why Transfer Files Without Internet?
Traditional cloud storage services (Google Drive, WeTransfer, Dropbox) force your data through a slow, two-step round trip: uploading across your home broadband uplink (often capped at 10–20 Mbps) to a remote corporate server, then downloading it again onto the receiving device.
Textunnel operates on a pure Local Area Network (LAN) peer-to-peer pipeline:
- Zero Broadband Bottlenecks: Transmits data directly through your local Wi-Fi router at hardware speeds (300 Mbps to 1,200 Mbps). A 5GB 4K video transfers in under 45 seconds.
- Zero Cellular Data Costs: Send hundreds of gigabytes over a mobile hotspot without consuming a single megabyte of your phone data plan.
- Understand the offline scope: Load the site first and exchange both Offline Connect QR codes. A reachable local route is required. This is not an independently audited environment for confidential or regulated data.
How to Transfer Files Offline in 3 Simple Steps
Connect to Same Wi-Fi
Ensure Device A and Device B are connected to the same Wi-Fi router or a shared mobile phone hotspot.
Open Textunnel & Pair
Open textunnel.com on both browsers. Scan the on-screen pairing QR code or enter the 6-character room ID.
Stream at Gigabit Speed
Drag and drop your files or folders. They stream directly across your local network at wire speed with automatic disk saving.
Technical Architecture: Local WebRTC & Host ICE Candidates
How does browser-based transfer function when the public internet is inaccessible?
Local Host Candidate Discovery
During peer connection establishment, WebRTC gathers host ICE candidates directly from your network interface (e.g. 192.168.x.x or 10.x.x.x), allowing direct UDP sockets to bind locally without STUN/TURN relays.
Stream Backpressure Engine
Uses bounded source reads and browser backpressure. The receiving browser needs disk saving for files over 256 MiB; available memory and storage still apply.
Offline File Transfer Options Compared
| Method | Internet Required | Transfer Speed | Hardware Cables / USB | Cross-Platform |
|---|---|---|---|---|
| Textunnel (Local P2P) | No (100% Offline LAN) | Device and network dependent | None (Wireless) | iOS, Android, Mac, Windows |
| Cloud Drives (Drive, Dropbox) | Mandatory | Slow (1-5 MB/s upload) | None | Yes |
| Bluetooth File Transfer | No | Extremely Slow (~200 KB/s) | None | Incompatible iOS ↔ PC |
| USB Flash Drive / OTG Cable | No | Fast | Requires physical adapters | Format conflicts (NTFS vs APFS) |
Frequently Asked Questions (FAQ)
Can I transfer files between devices without an internet connection?
Yes. Once the Textunnel web application is loaded into your browser (or cached via PWA), files stream directly between devices across your local Wi-Fi router or mobile phone hotspot without consuming any cellular data or needing public internet access.
How does offline local file transfer work without internet?
Transfer speed depends on the selected route, devices, browser and network. The same Wi-Fi does not guarantee a direct connection. Check the route badge; TURN and MQTT relay require explicit permission in each tab; Direct only disables content relay.
Can I use a phone hotspot with no cellular reception or data plan?
Yes. Turn on your smartphone's Personal Hotspot and connect your laptop or second device to it. Even if your phone has 0 bars of cellular service or mobile data turned off, a local Wi-Fi subnet is formed, allowing Textunnel to transmit files at high speeds.
Do I need to install an app on iOS or Windows to transfer offline?
No. Textunnel functions directly in standard web browsers including Safari, Chrome, Edge, and Firefox. There are no app store downloads, driver installations, or administrative permissions required.
Is there a limit on file size when transferring offline?
File size depends on the route and browser. After explicit relay permission, broker fallback accepts up to 25 MiB; share links and folder packing accept up to 256 MiB. Receiving larger room files requires a supported disk-saving API. Large-file speed and memory use are not guaranteed.
How fast is offline LAN file transfer compared to cloud drives?
Transfer speed depends on the selected route, devices, browser and network. The same Wi-Fi does not guarantee a direct connection. Check the route badge; TURN and MQTT relay require explicit permission in each tab; Direct only disables content relay.
Does offline file transfer work on airplanes or in remote outdoor areas?
Yes. As long as both devices share a local connection (such as connecting to an airplane's local Wi-Fi without buying the internet pass, or connecting to a portable travel router/hotspot), offline transfers work seamlessly.
Are my offline transfers encrypted and private?
WebRTC data channels use browser-negotiated DTLS transport encryption. Offline Connect can avoid online signaling after the site has been loaded and both QR codes exchanged over a reachable local route. It does not guarantee protection against compromised devices, browser extensions or unintended recipients; local history and saved files remain.
Can I transfer entire folders offline without manually zipping them?
Yes. Textunnel supports client-side folder drag-and-drop. The browser packages and streams directories on-the-fly directly to the receiving device.
What happens if a device goes to sleep during an offline transfer?
Textunnel integrates the Screen Wake Lock API to automatically prevent your phone or laptop screen from locking during active transfers, ensuring long file streams complete without interruption.