Compare Two CSV Exports by ID
Join two CSV exports on a key, flag changed columns, and isolate missing rows without leaving the browser.
Try it now
Try it now
Open CSV Join / Merge / Compare with a ready-to-run example.
When you need this
- You exported the same table from two systems and need to see what changed.
- You want to compare QA vs. production snapshots by id, email, or another key column.
- You need missing-row and duplicate-key checks before loading a spreadsheet into another system.
How to do it with Daily Developer Tools
- Paste the left and right CSV exports into CSV Join / Merge / Compare.
- Set the key column or key column list shared by both files.
- Run the comparison to inspect changed rows, missing rows, duplicate keys, and joined output.
Tips / common pitfalls
- Use a stable key such as id or email so changed rows are mapped correctly.
- Review duplicate-key warnings before trusting the change summary.
- Copy the joined CSV when you need to continue analysis in Excel or Sheets.
Examples & test data
CRM export vs. billing export
Input example (List 1)
id,email,status,plan 1001,alice@example.com,active,pro 1002,bob@example.com,active,starter 1003,carol@example.com,disabled,pro
Input example (List 2)
id,email,status,plan 1001,alice@example.com,active,team 1002,bob@example.com,active,starter 1004,dave@example.com,active,starter
Expected output
Changed rows: 1 Left only: 1 Right only: 1
FAQ
Can I compare on more than one key column?
Yes. Provide a comma-separated key list such as account_id,email.
Does it show which columns changed?
Yes. The diff output includes the changed columns and the left/right values.
Privacy-first: runs locally in your browser. No uploads.