Import and export

Export with Cmd/Ctrl+Shift+E.

Exporting

Exports honour the query currently in your tab. Filter to the documents you want, then export — you do not have to take the whole collection.

JSON

JSON export uses the Firestore wire format, which represents every type explicitly. This is the lossless option and the right default: a document exported to JSON and imported again is byte-for-byte the document you started with.

CSV

CSV is convenient and, on its own, lossy — a spreadsheet has no way to say “this is a timestamp with microsecond precision” or “this is an int64, not a float”.

FireFetch solves that with a tagging scheme. Non-scalar and precision-sensitive values are written with a type prefix:

• @json: for structured values such as maps and arrays
• @ts: for timestamps

Tagged CSV round-trips losslessly. If you open it in a spreadsheet, you will see the tags — that is the tradeoff, and it is why JSON remains the better choice when nothing needs to be read by a human.

Importing

Import supports three modes:

Mode	Behaviour
Create	Fail if a document already exists
Replace	Overwrite the document entirely
Merge	Update the fields present in the file, leave the rest alone

Run a dry run first. It reports exactly what would be created, replaced or merged, without writing anything.

Imports require write access on the target database and are recorded in the change history, so an import that goes wrong can be undone.