A surprising amount of localization work arrives as a spreadsheet: product catalogs exported from an online store, UI strings exported from a database, glossaries, survey questions, app store metadata. The files look simple, but one misplaced comma, a broken encoding or an overwritten ID column can corrupt an import. This guide explains the differences between CSV, TSV and XLSX and how to translate each one safely.
CSV, TSV and XLSX at a Glance
What is a CSV file?
CSV (comma separated values) is a plain text file where each line is a row and commas separate the columns. Text containing commas must be wrapped in quotes. It is the most common export format for e-commerce platforms, CRMs and databases. The format is described in RFC 4180, although many tools interpret it slightly differently.
What is a TSV file?
A TSV file (tab separated values) works the same way, but uses a tab character between columns instead of a comma. Because natural language text often contains commas but rarely contains tabs, TSV avoids most quoting problems, which makes it a popular choice for translation exchange, string exports and data pipelines.
What is an XLSX file?
XLSX is Microsoft Excel's Office Open XML workbook format. Unlike CSV and TSV it can hold multiple sheets, formatting, comments, formulas, hidden columns and data validation. It is easier for humans to work with, but more complex for automated processing.
TSV vs CSV: Which Is Better for Translation?
- Delimiters: translated sentences often add commas, which can break poorly quoted CSV files. TSV is more robust.
- Compatibility: CSV is supported almost everywhere; TSV is supported by most tools but sometimes needs an import setting.
- Regional settings: in many European locales, spreadsheet software uses a semicolon as the CSV separator because the comma is the decimal mark. TSV avoids this confusion.
- Readability: both are plain text; XLSX is better if reviewers will read the file directly.
Common Problems When Translating Spreadsheets
- Encoding: files saved in a legacy encoding turn accented letters and non Latin scripts into garbled characters. Always use UTF-8.
- Overwritten keys or IDs: translators accidentally edit SKU, key or ID columns, so the import no longer matches.
- Broken quoting: a stray quotation mark in a CSV cell shifts every following column.
- Formulas and numbers: Excel may convert codes such as 00123 into numbers or dates, or translators may overwrite formulas.
- Hidden content: hidden rows, columns and sheets get missed, or translated when they should not be.
- Length limits: product titles and app store fields often have character limits that are easy to exceed.
How to Translate CSV, TSV and Excel Files Step by Step
- Prepare the file. Save as UTF-8, remove unused columns and add a column with context or maximum length if possible.
- Upload it to a translation management system and choose which columns are source text, which are target, and which must stay untouched (IDs, keys, prices, URLs).
- Pre-translate repeated rows with translation memory; catalogs are full of repeated phrases such as sizes, materials and care instructions.
- Machine translate the rest with an AI translation engine guided by your glossary.
- Review in the CAT editor, where each cell becomes a segment and IDs are visible as context but protected.
- Run QA for numbers, placeholders, length limits and terminology with automated checks.
- Export in the original format with the same delimiter, encoding and column order, then test an import into the target system.
Typical Use Cases
E-commerce product catalogs
Store platforms export products as CSV with titles, descriptions, attributes and SEO fields. Translate the text columns, keep handles and SKUs, and reimport. Our ecommerce localization guide explains what else to adapt for each market.
Software strings
Some frameworks and databases export UI strings as CSV or TSV with a key column and one column per language. For structured formats, see also how to translate JSON files and PO files.
Glossaries and term lists
Terminology is often exchanged as CSV or XLSX before being imported into a term base. Learn more in our article on terminology management.
Bilingual review files
Excel is a convenient format for clients who want to review translations side by side, with comments in an extra column, before changes are imported back into the TMS.
Tips for Clean Spreadsheet Translation
- One language per column, one string per cell.
- Never merge cells in files intended for translation.
- Store numbers and codes as text where leading zeros matter.
- Add a context column; translators make fewer mistakes when they know where a string appears.
- Keep the original file as a reference and compare row counts after export.
Translate Spreadsheets With WordBeam
WordBeam imports CSV, TSV and XLSX alongside JSON, PO, XLIFF, DOCX and other supported formats. You choose source, target and locked columns, translators work with memory, glossary and AI engines, and the file comes back with the same structure, ready to import. Workflow automation can even pick up recurring exports automatically. Start free.
Frequently Asked Questions
What is a TSV file used for?
TSV files store tabular data as plain text with tabs between columns. They are used for data exchange, string exports and translation because tabs rarely appear in normal text.
How do I translate a CSV file without breaking it?
Use a translation tool that lets you select which columns to translate, protects all other columns and exports with the same delimiter and UTF-8 encoding. Avoid editing CSV files directly in Excel if they contain codes with leading zeros.
Can Excel files be translated with formatting intact?
Yes. A CAT tool or TMS extracts the cell text and writes translations back into the same cells, keeping sheets, formatting and formulas.