JSON + CSV Merger (Join by Key)
You have user records in JSON and account info in CSV; combine them on email or id. This tool joins a JSON array with a CSV by a common key, producing enriched output in either format. Like a poor-man's SQL JOIN, runs in your browser.
How to use the JSON + CSV Merger (Join by Key)
Paste a JSON array and a CSV. Pick the join key in each. Click Merge. Output combines fields from both records where the keys match.
Joining JSON and CSV on a shared key
Related data often arrives split across formats and systems — user records as a JSON array from one service, their account or billing details as a CSV export from another. Stitching them together by hand, matching each record on an id or email, is exactly the kind of tedious work a database JOIN would normally do for you.
This joins a JSON array with a CSV on a common key and emits the combined records in either JSON or CSV, like a lightweight SQL JOIN that runs entirely in the browser. It merges two different datasets keyed by a shared column; to deep-merge two JSON objects that overlap in structure, the JSON merge tool is the right one, and the CSV to JSON converter helps if you would rather convert first and merge later.
Common use cases
- Enrich records — add CSV account details to a JSON list of users by id.
- Combine exports — merge data pulled from two systems on a shared key.
- Join without a database — get JOIN-style output with no SQL setup.
- Pick the output — emit the merged result as JSON or as CSV.
- Reconcile sources — line up matching records to compare or combine fields.