CSVFixLab
Free browser-based CSV diagnostics

Find CSV import errors before your upload fails.

Check encoding, delimiters, broken quotes, inconsistent columns, and basic Shopify CSV issues directly in your browser. No account. No server upload required for CSV parsing.

Check a CSV nowSee reproducible test cases

Built for reviewable CSV repairs

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Local processing
Selected CSV contents are parsed in your browser.
✓
Row-level diagnostics
See the rows and parser evidence behind a failure.
✓
Safe repair only
Ambiguous quotes, row widths, headers, and unknown encodings block repair.
Quick CSV import check
Run a structural CSV preflight without sending the selected file to a CSVFixLab application server.
Local browser processing
Drop a CSV file hereor choose a file from your device
Auto mode confirms UTF-8 exactly. If the file is not UTF-8, choose its source encoding before downloading a repair.
Analyzing…
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CSV report

Health score reflects checks on this page; it does not guarantee import acceptance.

—data rows
—columns
—delimiter
—encoding

Fix the specific problem, not just the file

Use a focused tool when you already know what is going wrong.

Encoding Fix

Strictly confirm UTF-8 and convert a known legacy source encoding.

Delimiter Fix

Detect comma, semicolon, tab, or pipe separators and normalize safe files.

Broken Quotes

Locate missing or malformed quoted fields without guessing the edit.

Column Count

Find rows with too many or too few parsed fields.

Safe CSV Repair

Normalize only changes that can be made without inventing business data.

Shopify CSV

Check generic structure plus selected Shopify product CSV requirements.

Verify the tool with downloadable lab cases

The evidence library includes both successful repairs and cases where CSVFixLab intentionally refuses to guess.

Safe

Semicolon → comma

Same values, different serialization. Reproduce a safe repair.

Blocked

Wrong row width

See why missing business fields cannot be reconstructed safely.

Blocked

Broken quotes

See how one unclosed quote changes later record boundaries.

Confirm source

Windows-1252 → UTF-8

Test the rule that Auto never guesses a legacy encoding for repair.

Platform rule

Shopify missing Title

A valid CSV can still miss a platform-required header.

All lab cases

Download every fixture and reproduce the expected behavior.

Learn why the import fails

Use the guides for the syntax and the methodology page for CSVFixLab's repair boundaries.

Import Preflight Checklist

A repeatable sequence before a bulk CSV upload.

UTF-8 & Encoding

Understand garbled text and source-confirmed legacy conversion.

CSV Quoting

Learn how commas, line breaks, and double quotes interact.

Shopify CSV Errors

Separate local file problems from store-specific import rules.

Safe Repair Boundaries

See what can be normalized and what must come from source data.

Testing Methodology

See the exact conditions that enable or block repair downloads.

Why CSV imports fail even when the file opens normally

A spreadsheet can display a CSV without revealing structural problems that matter to another importer. A stray quote, inconsistent row width, legacy encoding, duplicate header, or unexpected delimiter can shift values or make an import fail.

What CSVFixLab does differently

CSVFixLab separates structural evidence from business meaning. It can normalize representations when field boundaries are proven, but it does not invent missing prices, SKUs, identifiers, titles, or other source data.

Private by design

The MVP parses the selected file in your browser using JavaScript and a Web Worker. The application does not need to upload CSV contents to a server for the checks shown here.

Transparent by design

The lab case library publishes the small fixtures behind key behaviors, while the methodology documents why some repairs are intentionally blocked.