Transfer Large Files Over LAN Without Internet

Need to move a 50 GB video file between two PCs on the same network? Cloud services like Google Drive or Dropbox require internet access, take hours to upload and download, and often have file size limits. USB drives are slow and require physical access.

CastAngel’s LAN file transfer solves this: direct PC-to-PC transfer over your local network, with no internet dependency and no file size limits.

How CastAngel File Transfer Works

CastAngel uses a chunked transfer protocol optimized for local networks:

• 4 MB chunks: Large files are split into 4-megabyte pieces for reliable transfer
• Resume on failure: If a chunk fails, only that chunk is retried — not the entire file
• Multi-user isolation: Each user gets their own folder on the destination PC’s desktop
• Cookie-based sessions: Multiple people can transfer files simultaneously without interference

The transfer speed depends on your network hardware:

Step-by-Step Guide

Step 1: Download and Run CastAngel on the Receiving PC

Download CastAngel and run the .exe file on the PC that will receive the files. Click Agree on the disclaimer.

CastAngel starts automatically and shows a tray icon.

Step 2: Note the Receiving PC’s IP Address

Right-click the CastAngel tray icon → Show IP and Port.

You’ll see:

IP: 192.168.1.35
Port: 12377 (screen casting)
Port: 12399 (file transfer)

Step 3: Open the Web Interface from the Sending PC

On the PC that has the files you want to send:

1. Open a web browser
2. Go to http://192.168.1.35:12377 (the receiving PC’s IP)
3. Enter a username and password — this creates your session
4. Click Login

Step 4: Upload Files

You’ll see the main interface with a file upload area:

1. Drag and drop files directly onto the upload area, or click Browse to select files
2. The upload starts immediately with a progress bar
3. Multiple files can be queued — they transfer sequentially
4. A Cancel button is available during transfer

Files are saved to the receiving PC’s desktop in a folder named after your username:

C:\Users\<user>\Desktop\YourUsername\
    ├── video_project.mp4
    ├── backup_archive.zip
    └── documents\
        ├── report.pdf
        └── spreadsheet.xlsx

Step 5: Verify Transfer

When the progress bar reaches 100%, the file is complete. On the receiving PC, check the desktop folder — your files are there, ready to use.

Tips for Faster Transfers

Use Wired Ethernet

Wi-Fi is convenient but slower and less stable than wired Ethernet. For large transfers (10 GB+), connecting both PCs to the router with Ethernet cables can cut transfer time by 3-5x.

Close Bandwidth-Heavy Applications

Streaming video, cloud sync (OneDrive, Dropbox), and large downloads compete for network bandwidth. Pause them during big transfers.

Transfer During Off-Peak Hours

If multiple people share the network, transfer large files when others aren’t using the network heavily — late at night or early morning.

Advanced: Managing User Accounts

CastAngel supports multiple user accounts for the file transfer service. Right-click the tray icon → Manage Accounts to:

• Add users: Create accounts with custom usernames and passwords
• Change passwords: Update credentials for existing users
• Delete users: Remove accounts (files already transferred remain on disk)

Each user’s files go to a separate folder on the desktop, so multiple people can transfer to the same receiving PC without mixing up files.

Security Considerations

Local Network Only

CastAngel’s file transfer listens on all network interfaces by default. On a trusted home or office LAN, this is fine. For public networks (coffee shops, hotels), consider:

• Using Windows Firewall to restrict access to specific IPs
• Setting strong passwords for all user accounts
• Disabling the service when not in use (right-click tray icon → Exit)

No Cloud, No Tracking

Unlike cloud-based file sharing services, CastAngel:

• Does not upload files to any server — transfer is direct PC-to-PC
• Does not track or log file contents — only transfer metadata (filename, size, timestamp)
• Does not require an internet connection — works on an isolated LAN

Troubleshooting

Transfer is slow

• Check if both PCs are using wired Ethernet
• Verify network speed: right-click tray icon → Network Diagnostics
• Close other network-heavy applications

Transfer fails midway

• Check available disk space on the receiving PC
• Ensure the receiving PC stays awake (disable sleep mode in Power Options)
• Check network stability — CastAngel retries failed chunks automatically

Can’t see the upload page

• Verify you’re using the correct IP and port (12377)
• Check if the receiving PC’s firewall allows port 12377
• Try a different web browser

Comparison: CastAngel vs Other Transfer Methods

CastAngel offers the simplicity of a USB drive with the speed of a network share — no configuration, no physical media, just run and transfer.

Next Steps

• Download CastAngel and try it yourself
• Learn about remote desktop setup for screen sharing
• Buy a license for permanent activation

Transferring large files over LAN doesn’t need to be complicated. With CastAngel, it’s as simple as drag, drop, done.