Troubleshooting library
Fix the file, not just the error message.
Start with the symptom you can see. Each walkthrough explains the likely cause, shows the malformed pattern, and gives you a way to verify the repair before the file reaches another system.
Spreadsheet import problem
CSV Opens in One Column? Fix the Delimiter
Fix a CSV that opens in one Excel column by identifying its real delimiter and exporting a clean comma- or semicolon-delimited file.
See the diagnosisCSV parsing error
Fix an “Unexpected Quote” CSV Error
Diagnose unexpected quote errors in CSV files and repair malformed quoted fields without changing valid text.
See the diagnosisCSV structure problem
Fix Inconsistent Column Counts in a CSV
Find CSV rows with too many or too few fields, identify the structural cause, and verify the corrected file before importing it.
See the diagnosisText encoding problem
Fix Garbled Characters in a CSV File
Repair mojibake, black diamonds, and broken accented characters by converting the CSV to a known text encoding.
See the diagnosisSpreadsheet type-conversion problem
Stop Leading Zeros Disappearing from CSV Values
Preserve ZIP codes, account numbers, SKUs, and phone fields that begin with zero when opening or importing CSV data.
See the diagnosisLarge-file workflow
CSV Too Large for Excel? Split It Safely
Split a large CSV into manageable files with headers preserved, then verify that no rows were skipped or duplicated.
See the diagnosisCSV header problem
Fix Duplicate Column Names in a CSV
Find repeated CSV headers and rename them deterministically so databases, pandas, and import tools do not overwrite fields.
See the diagnosisCSV cleanup problem
Remove Blank Lines from a CSV Without Losing Rows
Remove genuinely empty CSV records while preserving valid rows that contain blank fields or multiline quoted text.
See the diagnosisSpreadsheet security check
Detect Formula Injection in CSV Files
Scan untrusted CSV values for spreadsheet formulas before opening the file in Excel or sharing it with colleagues.
See the diagnosisJSON syntax problem
Find an “Unexpected Token” JSON Error
Locate malformed JSON syntax, understand the reported position, and validate the corrected document before conversion.
See the diagnosisJSON format mismatch
Convert NDJSON to a JSON Array or CSV
Recognize newline-delimited JSON, avoid the extra-data parse error, and convert one-object-per-line data correctly.
See the diagnosisData type problem
Fix CSV Date Format Import Errors
Standardize ambiguous and mixed date values before importing a CSV into a database, CRM, or spreadsheet.
See the diagnosisShopify import problem
Fix Shopify CSV Encoding and Illegal Quoting Errors
Convert a Shopify product or customer CSV to UTF-8, distinguish encoding damage from malformed quotes, and validate the file before importing it.
See the diagnosisSalesforce import problem
Fix Salesforce Data Loader CSV Encoding Errors
Prepare a UTF-8 CSV for Salesforce Data Loader and remove a UTF-8 byte-order mark when it causes an invalid-format error.
See the diagnosisHubSpot import problem
Fix Special Characters in a HubSpot Import CSV
Convert a HubSpot import file to UTF-8 and verify its headers, identifiers and character data before uploading it.
See the diagnosisGoogle Sheets size problem
CSV Too Large for Google Sheets? Split by Cell Count
Estimate CSV cells before import, split oversized data safely, and verify every chunk against Google Sheets limits.
See the diagnosisPython data workflow
Fix a pandas CSV Memory Error with Safe Chunks
Split or stream a large CSV for pandas without losing headers, changing identifier values or double-counting records.
See the diagnosisPostgreSQL import problem
Diagnose PostgreSQL COPY CSV Import Errors
Prepare a CSV for PostgreSQL COPY by checking headers, delimiters, null rules, encoding and rejected field values.
See the diagnosisSQLite large-file workflow
Convert a Large CSV to SQLite Without Opening It in Excel
Move a large CSV into SQLite, validate its schema and counts, and query the data without spreadsheet limits.
See the diagnosisData-cleaning symptom
Remove Leading and Trailing Spaces from CSV Fields
Trim accidental whitespace from CSV values while preserving meaningful spaces inside names, descriptions and codes.
See the diagnosisData-cleaning symptom
Standardize Inconsistent Capitalization in a CSV
Normalize CSV capitalization by column without damaging email addresses, identifiers, acronyms or human names.
See the diagnosisNumeric-format problem
Fix Decimal Commas and Thousands Separators in CSV Numbers
Normalize regional number formats without splitting decimal-comma values into extra CSV columns or changing their magnitude.
See the diagnosisMissing-data problem
Standardize CSV Null Markers Without Losing Empty Strings
Distinguish missing values from empty text, zero and literal markers such as NA, N/A, NULL and none.
See the diagnosisDeduplication decision
Choose Which Duplicate CSV Record to Keep
Define a defensible duplicate-record policy before deleting rows, including keys, precedence, merges and audit evidence.
See the diagnosisGeoJSON conversion problem
Fix CSV-to-GeoJSON Coordinate Errors
Prepare longitude and latitude columns for GeoJSON, reject invalid coordinates and verify point placement before publishing a map.
See the diagnosisvCard conversion problem
Fix CSV-to-vCard Missing Name and Contact Errors
Map CSV contact fields to vCard safely, provide the required formatted name and verify phone and email values before import.
See the diagnosisiCalendar conversion problem
Fix CSV-to-ICS Date and Time Errors
Prepare event dates, times and identifiers for iCalendar conversion and verify time zones and all-day event boundaries.
See the diagnosisParquet conversion problem
Fix CSV-to-Parquet Schema and Type Errors
Prepare mixed CSV columns for Parquet conversion by defining stable types, null handling and validation checks.
See the diagnosisSQLite conversion problem
Fix CSV-to-SQLite Conversion Errors
Correct duplicate headers, ragged rows and mixed column values before converting a CSV into a SQLite database.
See the diagnosisShopify size problem
Split a Shopify CSV That Exceeds the Import Limit
Split an oversized Shopify product, inventory or customer CSV while preserving headers, related rows and UTF-8 encoding.
See the diagnosisHubSpot size problem
Split a HubSpot Import File Safely
Prepare a HubSpot import that exceeds the file or row limits for your subscription without losing headers or unique identifiers.
See the diagnosisColumn-splitting problem
Split a Full Name Column in a CSV Safely
Split a full-name field into useful columns while preserving prefixes, compound surnames, single names and the untouched source value.
See the diagnosisEmpty-column problem
Remove Empty CSV Columns Without Shifting Data
Find columns that are genuinely empty across all records and remove them without changing field alignment or meaningful blank values.
See the diagnosisCSV sorting problem
Sort CSV Dates Chronologically, Not Alphabetically
Sort a CSV by real date values while detecting ambiguous formats, invalid dates and equal-date ordering.
See the diagnosisCSV filtering problem
Filter CSV Rows by Value Without Missing Matches
Filter CSV records using explicit text, numeric and date rules while preserving headers and documenting excluded rows.
See the diagnosisTable-reshape problem
Transpose or Pivot a CSV? Choose the Correct Reshape
Determine whether your data needs a mechanical transpose or a grouped pivot before changing its rows and columns.
See the diagnosisWide-table problem
Unpivot a Wide CSV into Tidy Rows
Convert repeated month, measure or category columns into key-value rows while preserving identifier columns and missing values.
See the diagnosisCSV join problem
Fix a CSV Join That Produces No Matches
Diagnose failed CSV joins by checking key types, whitespace, leading zeros, duplicates and normalization rules.
See the diagnosisExact-duplicate problem
Why “Duplicate” CSV Rows Are Not Being Removed
Find invisible differences that prevent apparently identical CSV records from matching exactly.
See the diagnosisDistinct-values workflow
Extract Unique Values from a CSV Column
Create a reliable distinct-value list by handling blanks, case, whitespace and frequency counts deliberately.
See the diagnosisCSV header problem
Fix Invalid CSV Header Names for Databases and Code
Create unique, stable CSV headers without losing column meaning or breaking downstream mappings.
See the diagnosisData-quality problem
Find CSV Outliers Without Deleting Valid Extremes
Detect unusual numeric values, distinguish errors from legitimate extremes and document every exclusion.
See the diagnosisCSV merge problem
Fix Header Mismatches Before Merging CSV Files
Align equivalent CSV columns, keep different meanings separate and prevent silent data loss during a multi-file merge.
See the diagnosisExcel conversion problem
Convert an Excel Workbook with Multiple Sheets to CSV
Export the intended Excel worksheet to CSV without accidentally omitting tabs, formulas or identifier formatting.
See the diagnosisExcel type-conversion problem
Preserve Leading Zeros When Converting CSV to Excel
Keep ZIP codes, phone numbers, SKUs and account identifiers as text during CSV-to-Excel conversion.
See the diagnosisJSON conversion problem
Convert Nested JSON to CSV Without Losing Structure
Choose a flattening rule for nested objects and arrays before converting JSON records into a tabular CSV.
See the diagnosisXML conversion problem
Convert Nested XML to CSV with the Correct Record Path
Select the repeating XML element that represents a row and handle attributes, namespaces and nested children deliberately.
See the diagnosisHTML table conversion problem
Fix HTML Table Conversion with Rowspan or Colspan
Convert an HTML table to CSV while detecting merged cells, repeated headers and text that does not map cleanly to a rectangular grid.
See the diagnosisPDF extraction problem
Fix Misaligned Columns After PDF-to-CSV Conversion
Review PDF table extraction for shifted columns, wrapped text, repeated page headers and OCR mistakes.
See the diagnosisOCR extraction problem
Correct OCR Errors When Converting a Table Image to Excel
Detect character substitutions, missing rows and merged cells after extracting a photographed or scanned table.
See the diagnosisSQL conversion problem
Fix SQL INSERT-to-CSV Parsing Errors
Extract tabular values from SQL INSERT statements while respecting quoted strings, NULLs, escapes and column order.
See the diagnosisGeoJSON conversion problem
Convert GeoJSON Properties to CSV Without Losing Geometry Context
Flatten GeoJSON feature properties into CSV while preserving geometry type, coordinates and feature identity.
See the diagnosisvCard conversion problem
Keep Multiple Phone Numbers When Converting VCF to CSV
Convert contacts with several phone numbers, emails and labels without overwriting repeated vCard properties.
See the diagnosisiCalendar conversion problem
Convert Recurring ICS Events to CSV Correctly
Decide whether to export recurrence rules or expanded event instances when converting an iCalendar file to CSV.
See the diagnosisParquet conversion problem
Prevent Type Changes When Converting Parquet to CSV
Export Parquet values to CSV while documenting timestamp, decimal, binary and null representations.
See the diagnosisPrivacy workflow
Anonymize Personal Data in a CSV Before Sharing
Replace direct identifiers, assess indirect re-identification risk and preserve only the fields needed for the stated use.
See the diagnosisPrivacy matching workflow
Hash CSV Identifiers for Privacy-Preserving Matching
Hash normalized identifiers consistently while understanding dictionary attacks, salts and irreversible mismatches.
See the diagnosisFile-security workflow
Encrypt a CSV Before Sending or Storing It
Encrypt a CSV with a strong passphrase, transfer the key separately and verify recovery before deleting the plaintext copy.
See the diagnosisSensitive-data redaction
Redact Email Addresses and Phone Numbers from CSV Text
Find sensitive patterns in structured fields and free text, review false positives and confirm that exported values are actually removed.
See the diagnosisData-subject workflow
Remove a Person’s Records from a CSV Dataset
Locate all records linked to a data subject, review dependencies and produce evidence of a controlled removal.
See the diagnosisData-quality diagnosis
Why Your CSV Data Quality Score Is Low
Turn a low quality score into specific checks for missing values, duplicates, inconsistent types and structural defects.
See the diagnosisMissing-data analysis
Find and Explain Missing Values in a CSV
Measure missingness by column and group, distinguish true nulls from parsing errors and decide what needs correction.
See the diagnosisType-inference problem
Find Mixed Data Types in a CSV Column
Detect columns containing incompatible numbers, dates, booleans and text before importing them into typed systems.
See the diagnosisFrequency-analysis workflow
Build a Frequency Table from a CSV Column
Count category values accurately after handling blanks, inconsistent labels and weighted versus unweighted records.
See the diagnosisCorrelation-analysis problem
Interpret CSV Correlations Without Misleading Conclusions
Check data types, missingness, outliers and subgroup effects before interpreting a correlation matrix.
See the diagnosisSchema-inference workflow
Generate a CSV Schema Without Misclassifying Columns
Infer a useful schema from CSV values while protecting identifiers, rare exceptions and nullable fields.
See the diagnosisPre-import validation
Validate a CSV Before Importing It
Check encoding, delimiters, quotes, headers, field counts and destination rules before a production import.
See the diagnosis