Hey Product Hunt 👋 I built this tool because I had to compare two massive CSV dumps with millions of rows of user data a while back. I couldn’t find a suitable UI tool. Excel would crash, and cloud tools were out of the question because the data was sensitive. So I resorted to CLI commands — slow and error-prone. Took me hours to ensure the data was correct. This tool is optimized for large CSV files, but works great with smaller ones too. Benchmark (on my MacBook M2): two 50M-row CSVs compare in ~30 seconds; on Windows, ~40 seconds. Two 1M-row CSVs take about a second. It runs entirely locally, so your data never leaves your computer. I’d love your feedback — especially on performance, features, or edge cases. Did I mention there's a 3-day free trial included? Thanks for checking it out! 🙏

Lake3Tools CSV Compare desktop app

Compare CSV files with 10s of millions of rows in seconds.

Compare CSV files with 10s of millions of rows in seconds.