Does CSV Header List upload my file or text to Tool-You servers?

No. CSV Header List runs in this browser tab. Files stay on the device. Limit note: Non-empty CSV text.

Should I use CSV Column Count instead of CSV Header List?

Use CSV Header List when you need List CSV headers one per line. Use CSV Column Count when you need Count columns in the header row. They share a category (Convert) but not the same job.

CSV Header List

List CSV headers one per line.

Splits the first CSV line into headers. Unlike CSV Column Count this prints names. Empty fails.

What CSV Header List does

Splits the first CSV line into headers. Unlike CSV Column Count this prints names. Empty fails.

The interactive controls for CSV Header List load after this article so crawlers still read the instructions. Path /convert/csv-header-list is the canonical address. Work happens on this device; Tool-You does not take a copy of the file or pasted text for CSV Header List.

How to use CSV Header List

Keep this tab on CSV Header List (/convert/csv-header-list). Pasting into the wrong Convert tool (for example CSV Column Count) changes the job.
Paste or type the input CSV Header List expects. Path hint: convert · csv header list. List CSV headers one per line.
Apply the CSV Header List action only. CSV to JSON is a different transform (Parse CSV into a JSON array of objects.). Splits the first CSV line into headers. Unlike CSV Column Count this prints names. Empty fails.
Copy the output of CSV Header List if you need it elsewhere. Size/complexity still follows: Non-empty CSV text.
If the text job is actually Count columns in the header row., leave CSV Header List and open CSV Column Count.

When not to use CSV Header List

Skip CSV Header List when a neighbor tool matches better — start with CSV Column Count or CSV to JSON — or when the description already warns the job will fail. In the tool’s own words: Splits the first CSV line into headers. Unlike CSV Column Count this prints names. Empty fails.

Questions about CSV Header List

What does CSV Header List do that other Convert pages on this site do not?: Splits the first CSV line into headers. Unlike CSV Column Count this prints names. Empty fails. Short version: List CSV headers one per line.
Does CSV Header List upload my file or text to Tool-You servers?: No. CSV Header List runs in this browser tab. Files stay on the device. Limit note: Non-empty CSV text.
Should I use CSV Column Count instead of CSV Header List?: Use CSV Header List when you need List CSV headers one per line. Use CSV Column Count when you need Count columns in the header row. They share a category (Convert) but not the same job.
What are the limits of CSV Header List?: Non-empty CSV text. Also: Splits the first CSV line into headers. Unlike CSV Column Count this prints names. Empty fails.