Paste or upload CSV
Drop in a .csv, .tsv, or plain text file. Auto-detect handles common delimiters, or you can choose the delimiter manually.
free tool · csv validator
Validate CSV files before they break your import.
Paste a CSV or upload a file and catch missing required values, invalid emails, duplicate keys, and row shape problems. The checks run locally in your browser.
No upload, no signupRequired column checksEmail validationDuplicate detection
01
How to validate a CSV file
Use this validator when you want to quickly understand why a customer CSV, export, or migration file may fail before it reaches your backend.
Choose validation rules
Enter required columns, pick an email column, and choose a unique column for duplicate detection.
Review issues or download clean rows
Copy the issue report for debugging, or download a filtered CSV containing only rows that passed the selected checks.
02
A CSV validator for the problems that block onboarding
The hard part of CSV import is not reading the file. It is catching the messy values while the user can still fix them. This tool shows those failures quickly.
Required fields
Check that important fields like name, email, company, plan, or account_id are present and filled in every row.
Invalid emails
Find email values that are missing a domain, extension, or @ symbol before they hit your product database.
Duplicate detection
Use a unique column such as email, sku, account_id, or external_id to spot duplicate records inside the file.
Row shape problems
Catch rows with too many or too few cells compared with the header row, which often means a delimiter or quote issue.
Private validation
The CSV is parsed and checked in the browser. It is useful for sensitive customer exports and internal data samples.
Clean row export
Download rows that passed the checks so you can continue testing, debugging, or importing a safer subset.
03
Common CSV validation checks
These checks map closely to the failures SaaS teams usually see during account setup, data migration, and recurring customer imports.
Onboarding imports
Validate required columns and emails before a customer uploads contacts, members, leads, or accounts.
Migration files
Check duplicate IDs and missing fields before loading a legacy export into a new database.
Support debugging
Paste a customer CSV and send back a precise row-level issue report instead of asking for screenshots.
Importer QA
Generate realistic failing files so your product importer handles bad rows gracefully.
04
Questions about this tool
Short answers for the things people usually ask.
Is this CSV validator free?
Yes. It is free, requires no signup, and runs locally in your browser.
Is my CSV uploaded anywhere?
No. The validation happens in JavaScript on this page. Your CSV is not sent to Rowslint or any external server.
What can it validate?
It checks required columns and required values, email format, duplicate values in a selected column, and rows that do not match the header shape.
Can I validate semicolon or tab-separated files?
Yes. Use auto-detect or choose comma, semicolon, tab, or pipe delimiters manually.
How do I validate CSV files inside my own product?
Rowslint embeds validation in your import flow so customers can fix bad rows before anything reaches your backend.
from one-off tools to product workflows
Let customers import CSV and Excel files inside your app.
Rowslint adds mapping, validation, and clean row delivery to your product so your team is not building an importer from scratch.