SPARKPOND / DATA TOOLS
Free Online CSV, JSON & Excel Tools
Clean, analyze, convert, split and merge data privately in your browser. No uploads, no account and no download paywall.
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24 matching tools
Clean and repair CSV files
View 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.
Use this tool →02Remove 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.
Use this tool →03Find 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.
Use this tool →04Normalize 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.
Use this tool →05Fix 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.
Use this tool →06Change 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.
Use this tool →07Clean 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.
Use this tool →08Remove 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.
Use this tool →09Remove 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.
Use this tool →Analyze and validate data
View category →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.
Use this tool →02Filter 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.
Use this tool →03Sort 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.
Use this tool →04Compare 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.
Use this tool →05Validate 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.
Use this tool →Organize CSV files
View category →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.
Use this tool →02Split 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.
Use this tool →03Merge 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.
Use this tool →04Join 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.
Use this tool →05Clean 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.
Use this tool →Convert data
View category →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.
Use this tool →02Convert 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.
Use this tool →03Convert 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.
Use this tool →04Convert 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.
Use this tool →05Convert 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.
Use this tool →Understand before fixing
Common CSV 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 guide →How to Fix UTF-8 and Windows-1252 CSV Encoding
Garbled text appears when bytes are decoded with a different character encoding from the one used to create the file.
Read guide →CSV Comma vs Semicolon: Which Delimiter Should You Use?
Both formats are valid delimited text; compatibility with the destination matters more than the extension.
Read guide →How to Preserve Leading Zeros in CSV Files
Leading zeros disappear when identifiers are interpreted as numbers rather than text.
Read guide →How to Remove Duplicate Rows from a CSV
Duplicates must be defined by all columns or by stable business keys before rows are removed.
Read guide →How to Convert Excel XLSX to CSV Without Excel
A browser can read XLSX values locally and serialize each selected sheet as a separate CSV.
Read guide →