This web app will occasionally crash on large files. This is due to Chrome/Edge browser limitations.

Chrome/Edge work great until you start to exceed around 6,000,000 lines.

Firefox handles large files better but the "Dupe" options becomes very slow above around 6,000,000 lines.

My recommendations for large files exceeding around 6,000,000 lines:
1. Use the 64-bit version of Firefox.
2. Use a Win11 PC with at least 16GB of RAM.
3. If using the "Dupe" options, just wait for it to complete.