You do not yet know what is wrong.
Start with CSV Profiler.
SPARKPOND / CATEGORY
Free Online CSV Tools
Start with the exact problem instead of a generic editor. Each tool opens the same private workspace with formats, options and explanations tailored to that task.
Problems covered
What you can solve
- ✓ Clean inconsistent rows and headers.
- ✓ Analyze quality before an import.
- ✓ Convert CSV, JSON, TSV and XLSX.
- ✓ Split, merge, join or compare files.
24 tools
Tools in this category
Free Online CSV Cleaner
Clean CSV or TSV files locally, preview ordered repairs and download a checked CSV without an account. Duplicates, blanks, headers and dates stay under your control.
Open →Profile and Analyze a CSV Online
Profile CSV or TSV data locally with row, column, type, missing, distinct, duplicate and structural metrics. Review invalid examples without an account.
Open →Remove Duplicate Rows from a CSV
Remove exact or key-based duplicates from CSV or TSV locally. Preview the row-count impact, keep the first, last or most complete row, and download without an account.
Open →Find and Fix Missing Values in a CSV
Find blank, null, N/A, NA and dash markers in CSV or TSV locally. Keep, fill, remove or quarantine affected rows and download checked outputs without an account.
Open →Normalize CSV Dates to ISO 8601
Normalize CSV or TSV dates to ISO 8601 locally after explicitly confirming a day-first or month-first convention. Preview changed cells without an account.
Open →Fix Garbled CSV Characters and Encoding
Fix UTF-8, BOM, Windows-1252 or Latin-1 CSV text locally. Compare decoding previews for é, ’ and Â, then export UTF-8 without an account.
Open →Change a CSV Delimiter Online
Change a CSV or TSV delimiter locally between comma, semicolon, tab and pipe. Preserve quoted separators, preview columns and download without an account.
Open →Clean and Rename CSV Column Headers
Clean empty, duplicate or padded CSV headers locally. Preview unique old-to-new column names and download a checked CSV without an account.
Open →Remove Spaces from CSV Cells
Trim leading, trailing and non-breaking whitespace from selected CSV or TSV columns locally. Highlight changed cells and export without an account.
Open →Remove Empty Rows from a CSV
Remove fully blank or whitespace-only CSV rows locally after reviewing the count. Configure null markers and download a checked CSV without an account.
Open →Filter CSV Rows Online
Filter CSV or TSV rows locally with equals, contains, ranges, dates, regex and AND/OR rules. Keep or remove matches and download without an account.
Open →Sort a CSV by Multiple Columns
Sort CSV or TSV locally by multiple text, number or date columns. Control direction, empty values and stable priorities, then download without an account.
Open →Extract and Reorder CSV Columns
Select, remove and reorder CSV or TSV columns locally. Preview the output schema, optionally rename fields and download without an account.
Open →Split a Large CSV File Online
Split CSV locally by row count, part count, approximate bytes or column value. Repeat headers, preview ZIP contents and download without an account.
Open →Merge Multiple CSV Files Online
Merge multiple CSV or TSV files locally with reordered, missing or extra columns. Review schema mapping and file order, then download without an account.
Open →Join Two CSV Files by a Common Column
Join two CSV or TSV files locally with inner, left, right or full joins. Preview duplicate keys, unmatched rows and column collisions without an account.
Open →Compare Two CSV Files Online
Compare two CSV or TSV versions locally by a chosen key. Find added, removed and changed rows, inspect duplicate keys and export a report without an account.
Open →Validate a CSV File Online
Validate CSV or TSV locally with required, type, range, length, regex, allowed-list and cross-column rules. Export valid and invalid rows without an account.
Open →Convert CSV to JSON Online
Convert CSV or TSV to JSON locally as objects, arrays or NDJSON. Control empty fields, numbers and booleans while preserving long IDs and leading zeros, no account needed.
Open →Convert JSON to CSV Online
Convert JSON arrays or NDJSON to CSV locally. Flatten nested objects with path notation, review arrays and missing keys, then download without an account.
Open →Convert CSV to Excel XLSX
Convert CSV or TSV to Excel XLSX locally with a chosen sheet name, practical widths, frozen headers and formula-safe text. Download without an account.
Open →Convert Excel XLSX to CSV
Convert Excel XLSX sheets to CSV locally without running formulas. Choose sheets, inspect cached values and dates, and download checked CSV files without an account.
Open →Convert TSV to CSV Online
Convert TSV files or tab-separated pasted text to CSV locally. Preserve quoted tabs and special characters, choose the output delimiter and download without an account.
Open →Clean Multiple CSV Files at Once
Apply one local cleaning recipe to multiple CSV files. Check schema compatibility, review per-file reports and download a ZIP with a manifest, no account needed.
Open →Choose well
Which tool should you use?
Several repairs are needed.
Use CSV Cleaner.
Only the format must change.
Choose a converter.
Guides
Understand these problems
Why a CSV Opens in One Column and How to Fix It
A CSV usually opens in one column because the file delimiter differs from the delimiter expected by the spreadsheet application.
Read →How to Preserve Leading Zeros in CSV Files
Leading zeros disappear when identifiers are interpreted as numbers rather than text.
Read →CSV Formula Injection: Risks and Safe Exports
A spreadsheet may interpret cells beginning with =, +, -, @, tab or carriage return as formulas when a CSV opens.
Read →FAQ
Category questions
Are these tools free?
Yes. There is no account or download paywall.
Are files uploaded?
No. File processing runs in the browser.
Which tool should I try first?
CSV Profiler is a read-only starting point; CSV Cleaner combines several explicit repairs.