Free · No signup · Runs in your browser
Base64 a CSVColumn
Encode or decode a single column to Base64 without uploading your file anywhere.
Encode or decode a single column to Base64 without uploading your file anywhere.
Pick a column, choose encode or decode, and download the result. Everything runs locally in your browser — no server, no upload, no trace.
Drop in or paste your CSV. The tool reads it entirely in your browser and lists every column for you to choose from.
Select the column, then choose Encode to turn values into Base64 or Decode to turn Base64 back into text. Tick Keep original to write to a new column instead of overwriting.
Download a clean RFC-4180 CSV with the Base64-encoded or decoded column. Round-trips are lossless and UTF-8 safe.
Base64 is the standard way to move text and binary-ish payloads through systems that only accept plain ASCII. Doing it client-side keeps sensitive values on your machine.
Accents, CJK characters, and emoji survive a full encode/decode round-trip. The encoder converts to UTF-8 bytes before encoding, so nothing gets corrupted.
Encode then decode returns the exact original string. Empty cells stay empty, and invalid Base64 is passed through untouched instead of throwing.
Replace the column in place for a quick transform, or add a new _base64 / _decoded column so you keep the source values alongside the result.
No backend, no upload, no logging. The CSV is parsed and transformed entirely in your browser tab, so confidential columns never leave your device.