Base64 to CSV

Paste a Base64 string and decode it back to CSV text, with a live table preview. Everything runs in your browser — nothing is uploaded.

How to decode Base64 to CSV

Paste your Base64 into the input above. The tool Base64-decodes it to raw bytes locally, interprets those bytes as UTF-8 text, and shows the resulting CSV in the output box. Click Download CSV to save a .csv file you can open in Excel or Google Sheets, or Copy to copy the text.

Previewing the CSV as a table

Below the source box, the decoded CSV is rendered as a table so you can eyeball the data at a glance. The first row is treated as the header. The preview splits on commas and understands basic double-quoted fields that contain commas — it's a quick visual check, not a full CSV engine. For large files, only the first 50 rows are shown to keep the page fast; the full data is always available in the output box and the download.

Is this private?

Yes. Decoding runs fully in the browser with JavaScript — your Base64 and the resulting CSV are processed locally and nothing is uploaded to any server. You can confirm in DevTools → Network: decoding fires no request.

Frequently asked questions

How do I convert a Base64 string to a CSV file?

Paste your Base64 into the input above. The tool decodes it to UTF-8 text locally and shows the CSV in the output box, plus a live table preview. Click Download CSV to save it as a .csv file, or Copy to grab the text.

Why are my columns split wrong?

The table preview splits on commas and handles basic double-quoted fields containing commas. If your file uses a different delimiter (semicolons, tabs) or complex quoting, the preview may split columns imperfectly. The downloaded and copied CSV text is always exact — only the on-page preview is simplified.

Can I download the decoded CSV?

Yes. After decoding, click Download CSV to save the decoded text as a .csv file, ready for Excel, Google Sheets, or any spreadsheet program. You can also click Copy to copy the CSV text to your clipboard.

Is my data uploaded?

No. Decoding runs entirely in your browser with JavaScript. Your Base64 and the resulting CSV never leave the page — nothing is sent to any server. You can verify in DevTools → Network that decoding fires no request.