Desktop App forLarge MBOX Files
Split MBOX files of any size efficiently and securely. No browser limitations, optimal performance, supports files over 10+ GB without issues.
Unlimited File Size
Even 50+ GB files are processed without problems
10x Faster
Native performance without browser overhead
100% Offline
Your data never leaves your computer
Why a Desktop App?
Browsers have technical limitations when processing large files. Here's the complete technical transparency:
RAM Limitation
Browsers load entire files into memory. 5 GB file = 5+ GB RAM usage.
JavaScript Single-Thread
Intensive operations completely block the user interface.
Browser Security Limits
Modern browsers limit memory access to prevent crashes.
Garbage Collection
JavaScript's automatic memory management is inefficient with large datasets.
📈 Result: Files over 2 GB: 80%+ failure rate in browsers
Stream Processing
Loads only 1-5 MB chunks into memory, processes continuously.
Multi-Threading
Parallel processing without UI blocking through worker threads.
Native System API
Direct filesystem access without browser sandbox limitations.
Optimized Memory Management
Manual control over memory allocation and deallocation.
Total Data Privacy
Your file never leaves your device. Splitting runs 100% locally using your computer’s CPU and disk. No data is ever uploaded or processed in the cloud or Server.
🚀 Result: Files up to 100+ GB are processed reliably
How to Use the Desktop App
Three simple steps for professional MBOX splitting
Download & Install
Download the app for your operating system and install it. No additional software or dependencies required.
Authentication
Log in here on the website and copy your authentication token. Paste it into the desktop app.
MBOX Splitting
Select your MBOX file, set the target size, and start the split. The app works reliably even with huge files.
Downloads
Available for all major operating systems
Windows 10 or newer
Free • Open Source • No registration required
macOS 10.15 or newer
Free • Open Source • No registration required
Ubuntu 18.04+ or equivalent
Free • Open Source • No registration required
Ready for Professional MBOX Splitting?
Download our desktop app and process MBOX files of any size reliably.
Meet MBOX Viewer
View, manage, and export your MBOX files directly in your browser - completely free and unlimited
MBOX Viewer
The perfect companion to our MBOX Splitter. View and manage your email archives without importing them into any email client.
No File Size Limits
Process MBOX files of any size - even hundreds of gigabytes. Everything runs locally in your browser.
100% Private & Secure
Your emails never leave your computer. All processing happens locally in your browser - no uploads, no cloud storage.
Edit & Export
Delete unwanted emails, download attachments, and export a cleaned-up version of your MBOX file.
💡 Pro Tip: Use MBOX Splitter to divide large archives, then MBOX Viewer to manage and clean them up!