CSV Join by Key
Join two CSV tables by exact key columns using inner, left or full joins, with duplicate-key checks.
Start with your input
Edit the example or replace it with your own text.
Choose your options
These settings are optional. Keep the defaults to get started.
How to use CSV Join by Key
- Paste the example or your own input.
- Choose the options that match your task.
- Run the tool, review the result, then copy or download it.
When to use CSV Join by Key
Join related exports when one table contains names and another contains account details, prices or departments. Choose one key column in each table; the names can differ. A left join keeps every first-table record, an inner join keeps matched records, and a full join also includes unmatched second-table records. Matching uses exact text, so leading zeros remain significant.
How to interpret the result
Both tables need unique, non-empty keys because this tool performs a one-to-one join rather than expanding many-to-many combinations. All columns are retained, including both key columns; conflicting right-side headers receive a unique suffix. Missing cells from unmatched rows are empty strings. Inputs use comma-separated CSV with a header row and may contain quoted commas or multiline values. Output is downloadable CSV; review it before importing into another system.
Example input
id,name 1,Ada 2,Grace
What should I check before using the output?
Both tables need unique, non-empty keys because this tool performs a one-to-one join rather than expanding many-to-many combinations.
Is input uploaded?
Processing takes place in your browser. This tool does not send your input or selected files to a conversion API.