Tested workflows
CSV guides
Short, task-specific explanations linked directly to the local tools and sample inputs used to verify them.
Xero CSV import guide
Review import formats and sample files before preparing a CSV for Xero.
How to Open a Large CSV File Without Freezing Excel
Open and inspect a large CSV in a browser worker, understand memory limits and avoid incomplete exports.
Fix CSV Special Characters and UTF-8 Problems in Excel
Diagnose UTF-8, UTF-16, Windows-1252 and Shift_JIS CSV files and export an Excel-friendly UTF-8 BOM.
CSV Delimiters: Comma, Semicolon, Tab or Pipe
Understand CSV delimiter detection and fix files that open as one column or split values incorrectly.
Fix a CSV That Opens in One Column in Excel
Find the actual CSV delimiter, preview the columns and fix comma, semicolon or tab-separated files before reopening them in Excel.
Keep Leading Zeros When Opening CSV Files in Excel
Preserve ZIP codes, SKUs, account numbers and long identifiers when moving CSV data into Excel.
Convert a Semicolon-Delimited CSV to Comma-Delimited CSV
Detect semicolon-separated data, preserve quoted punctuation and export a standard comma-delimited CSV locally.
How to Merge Multiple CSV Files with Different Columns
Combine CSV files by header union, common columns or physical position without breaking multiline fields.
How to Convert Nested JSON to CSV
Choose an array path, flatten nested objects and preserve arrays when converting JSON records to CSV.
How to use these guides
Start with the symptom you can observe: unreadable characters, a file that opens as one column, a workbook that freezes, mismatched headers or nested JSON that does not fit a table. Each guide explains the underlying boundary, gives a repeatable sequence and links to the matching local tool. Use the verification checks after every conversion instead of judging the result from the first few visible rows.
Safe examples, not production data
Downloadable fixtures contain synthetic values and deliberately include useful edge cases such as quoted delimiters, Unicode text and differing headers. They let you understand a workflow before opening a sensitive file. When reproducing a problem for support, modify one of these examples or create a minimal fictional sample rather than sharing customer, financial or operational data.
The complete fixture collection, expected parsing outcomes, checksums and versioned ZIP are available in the CSV Edge Case Test Dataset.