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Fix CSV encoding online — free, no upload

Nothing uploadedTested up to 150 MB

Detect CSV encoding, delimiter, and quoting problems, then download a normalized UTF-8 file without uploading it.

Fix garbled CSV text such as é showing as é by decoding one file entirely in your browser without uploading it, up to 150 MB, then downloading a normalized UTF-8 CSV. Automatic detection trusts UTF-8, UTF-16LE, or UTF-16BE when a BOM is present; otherwise it accepts strict UTF-8 and falls back to windows-1252 when UTF-8 decoding fails. The tool processes one file at a time. If the selected or BOM-declared encoding still produces replacement characters for bytes it cannot decode, those characters are kept in the output and reported so the damage is visible rather than hidden. A repaired file can be larger than the original: windows-1252 characters may take more bytes in UTF-8, and the configured output ceiling is sized separately for that expansion.

Processed locally in your browser

CSV encoding and delimiter doctor

Diagnose uncertain text encoding, separators, and quotes, then write a normalized UTF-8 CSV.

Results will appear here

Add valid data in the workspace above to preview and download the result.

Repair CSV encoding and separators without changing cell content

  1. 1

    Choose the CSV with broken characters or separators.

  2. 2

    Review the detected encoding, method, and delimiter confidence.

  3. 3

    Override uncertain source settings when necessary.

  4. 4

    Choose the output delimiter, BOM, and line endings.

  5. 5

    Download the normalized UTF-8 CSV.

Built for the real task

  • BOM-first encoding detection
  • Consistency-based delimiter scoring
  • Quoting diagnostics and normalization
  • Local UTF-8 output with optional BOM

See the transformation

Broken text and mixed separators become one reliable CSV

Repair garbled text and inconsistent separators while leaving the actual cell values alone.

Input
name;city;note
José;München,West;"ready"
Chloë|Zürich;review
Result
name;city;note
José;"München,West";ready
Chloë;Zürich;review

Browser limits

Files are limited to 150 MB to protect browser stability, especially on phones. Processing stays on this device.

BOM-first encoding detection

Detect CSV encoding, delimiter, and quoting problems, then download a normalized UTF-8 file without uploading it.

Private by design

The selected file is not uploaded to Nablyx.

Processed locally in your browser

No. This tool reads and transforms the file locally in your browser.

Common uses

  • BOM-first encoding detection
  • Consistency-based delimiter scoring
  • Quoting diagnostics and normalization
  • Local UTF-8 output with optional BOM

Does this tool clean or rewrite my data?

No. It only decodes, re-delimits, and normalizes CSV quoting. Cell content is otherwise unchanged; use Clean CSV for whitespace, blank rows, or uneven columns.

Ready to work on your file?

Return to the workspace and process it locally.

Fix CSV encoding