Guides for the files other programs break.
Leading zeros, dates, encodings, huge files, SQL and conversions — what goes wrong with data files, why, and how to keep your data intact.
Excel removes leading zeros. Here is how to keep them.
Why Excel turns 00731 into 731 when it opens a CSV, how to stop it in Excel, and how to open and save CSV files on a Mac with every leading zero kept.
Read →GuideStop Excel turning your data into dates.
Excel converts fractions, ranges, gene names and product codes into dates when it opens a CSV. Why it happens, how to prevent it, and how to keep values as written.
Read →GuideLong numbers lose their last digits. Here is why.
Excel keeps only 15 digits, so long IDs, order numbers and card-like numbers turn into scientific notation and lose digits. Why, and how to keep every digit of a CSV.
Read →GuideZürich instead of Zürich: what went wrong, and how to fix it.
Why ü becomes ü and é becomes é when a CSV is opened, how to tell UTF-8 from Windows-1252, and how to open and save a CSV in the right encoding on a Mac.
Read →GuideOpen a CSV of millions of rows on a Mac.
Excel stops at 1,048,576 rows and many editors freeze on big files. How to open, search, filter and query a CSV of millions of rows on a Mac.
Read →GuideSemicolon or comma: the European CSV, explained.
Why European Excel writes CSV with semicolons, why a file opens as one column, and how to read and write semicolon, comma and decimal-comma CSV correctly on a Mac.
Read →GuideQuery CSV files with SQL — without a database.
Run SQL on CSV, Excel and Parquet files on your Mac without importing them into a database: joins across files, GROUP BY, MySQL functions, views and exports.
Read →GuideCompare two CSV files, and see exactly what changed.
Compare two versions of a CSV or Excel file on a Mac — rows matched by a key column, columns by name, changes marked character by character.
Read →GuideSplit a large CSV into smaller files.
Split a big CSV into files of a fixed number of rows on a Mac — each with the header row and the original separator and encoding — for uploads, imports and Excel.
Read →GuideConvert a CSV to any of 38 formats.
Convert CSV files to Excel, JSON, Parquet, SQL inserts, SPSS, PDF and 32 other formats on a Mac — choosing rows, columns and their order, with saved presets.
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