ConvertCSV

Privacy Tools

Hash CSV Columns

SHA-256 hash selected columns for irreversible identifiers. Runs locally in your browser — nothing is uploaded for processing.

Input

Paste CSV or upload a file

Options

Output Preview

Result

Run the tool to preview output here.

Hash CSV Columns

Hash CSV Columns replaces selected fields with SHA-256 hex digests so the same input always maps to the same hash in one session’s algorithm.

Everything runs in your browser. File contents are not uploaded to a server for this tool.

Key features

  • Client-side processing
  • Copy or download results
  • Works with paste or upload where applicable

About the CSV to CSV format

Hashing is one-way; you cannot recover the original value from the digest.

Common use cases

  • Joining datasets without sharing raw IDs
  • Stable anonymous keys

How to use this tool

  1. Provide input (CSV, schema, or ciphertext).
  2. Set options if shown, then run the tool.
  3. Copy or download the result.

Tips for best results

  • Hashing does not protect against rainbow tables for low-entropy values — add a secret only in offline tooling if needed.
  • Preview output before sharing or importing.

Common pitfalls

Keep a copy of the original file — transforms can be hard to reverse.

Frequently asked questions

Is my data uploaded?

No. Processing stays in your browser tab.

For more background on data formats and conversion workflows, read our format guides or browse the converter blog for step-by-step walkthroughs linked to each tool.