Fast Processing of Large Files

EmEditor is highly optimized to be able to process large files quickly. It can handle multiple GB files without any problem. Optimized algorithms, multithreading, and SIMD instructions are what makes EmEditor fast. The benchmarks below show how fast EmEditor is at various tasks.

All benchmarks were performed on a Ryzen 9 7900X machine with 64 GB RAM and an SSD, on Windows 11 64-bit. Each benchmark was sampled 5 times and the average time is shown.

Open file

You can view and edit a file before EmEditor has finished reading the entire file. That means you can start editing a 50 GB file instantaneously. Operations on the entire file such as Sort may only be used after a file has finished loading. The benchmarks below show how long it took for EmEditor v22.1.0 to finish loading a file.

  • Open a 1 GB file
  • Open a 50 GB file
  • 0.131 seconds
  • 16.313 seconds


EmEditor’s Sort and Delete Duplicate Lines commands are optimized for large files. The benchmarks of these commands on a 202 MB, 1 million line file, show how they have improved over time to become more optimized.

  • EmEditor v12.0.11
  • Sort A to Z
  • Delete Duplicate Lines
  • EmEditor v12.0.11
  • 8.08 seconds
  • 8.63 seconds
  • EmEditor v22.1.0
  • 0.019 seconds
  • 0.031 seconds


Two benchmarks for the Find feature in v22.1.0 were done for two different search strings, both on the same 1 GB, 5 million line file.

  • Find the letter a, select all 32,264,754 matches
  • Find an 8 character unique string
  • 1.453 seconds
  • 0.319 seconds

CSV operations on real-world data

These benchmarks were done on a 10.8 GB, 90.2 million record CSV file published by the CDC.

  • Extract Frequent on column race_ethnicity_combined
  • Sort by Date and Time Oldest to Newest on column cdc_case_earliest_dt
  • 26.634 seconds
  • 33.050 seconds