Free · No sign-up · Browser-only

The Excel Cleaner your data deserves

Upload a messy Excel or CSV file, choose your cleaning rules, and download polished data in seconds — no formulas, no scripts, no account needed.

Files never leave your device
Cleans thousands of rows instantly
CSV, XLSX & XLS supported
1Upload
2Configure
3Download

Drop your file here

or browse to upload

.CSV.XLSX.XLS· Max 10MB

Everything you need to clean messy data

Whether you're preparing a CSV for import, fixing a client-supplied spreadsheet, or tidying up exported records, this tool covers the most common data quality issues in one pass.

Instant Duplicate Detection

Automatically scan your entire spreadsheet for exact duplicate rows and remove them in a single click — whether you have 100 records or 100,000.

Smart Format Standardization

Normalize date formats to ISO standard, strip currency symbols from numbers, and unify text casing so your data is consistent throughout.

Runs 100% in Your Browser

Your files never leave your device. All processing happens locally in your browser — no servers, no uploads, no privacy risks.

Data Quality Scoring

See a completeness score for every column so you can quickly spot where your dataset is sparse or missing values before you export.

Before & After Preview

Review exactly what changed before downloading — changed cells are highlighted so nothing slips past you unnoticed.

Export to CSV or Excel

Download your clean data as a properly formatted .csv or .xlsx file, ready to drop into any database, BI tool, or workflow.

How it works

Clean your spreadsheet data in four simple steps — no technical knowledge needed.

01

Upload your file

Drag and drop or browse to select a .csv, .xlsx, or .xls file. Files up to 10MB are supported.

02

Choose your cleaning rules

Toggle options on and off — remove duplicates, fix whitespace, normalize dates and numbers, standardize case, and more.

03

Preview the changes

Review a side-by-side view of your original data and the cleaned version, with changed cells highlighted in cyan.

04

Download clean data

Export your polished spreadsheet as a CSV or Excel file with a single click. No account required.

Why clean data matters — and how this tool helps

If you've ever imported a CSV into a database only to find half your records errored out, or tried to analyze a spreadsheet where dates were in three different formats, you know exactly how frustrating dirty data can be. A good CSV cleaner takes the manual grunt work off your plate so you can focus on what the data actually means.

This Excel cleaner was designed for analysts, developers, and anyone who regularly works with exported reports, form submissions, CRM exports, or any other spreadsheet data that arrives in less-than-perfect shape. Common issues like duplicate records, inconsistent capitalization, numbers stored as formatted text, and stray whitespace around values are all handled automatically — without you having to write a single formula or script.

Common spreadsheet problems this tool solves

Duplicate rows are perhaps the most common data quality issue. They creep in through repeated exports, copy-paste errors, or system syncs, and can skew aggregations, inflate counts, and cause database import failures. The duplicate removal feature compares entire rows and removes exact matches instantly.

Whitespace problems are trickier because they're invisible. A cell that looks like it says "New York" might actually contain " New York " with leading and trailing spaces. This breaks exact-match lookups and joins. The whitespace trimmer normalizes all text values so they match reliably.

Date formatting inconsistencies are especially painful when combining data from multiple sources. One system might export 01/15/2024, another 2024-01-15, and a third 15 Jan 2024. The date normalization feature converts detected dates into the clean YYYY-MM-DD ISO standard so they sort and parse correctly everywhere.

Number cleaning handles currency symbols, thousand-separator commas, and extra whitespace inside numeric fields — transforming "$1,250.00" into "1250.00" so the value can be used in calculations or imported into a numeric database column without errors.

Privacy-first design

Unlike many online data processing tools, this CSV cleaner never sends your file to a server. All parsing, cleaning, and export happens entirely within your browser tab using client-side JavaScript. That means your data — whether it contains personal information, financial records, or proprietary business data — stays entirely on your device at all times.

Who uses this tool

Data analysts use it to prep CSV exports before loading into BI tools like Tableau or Looker. Developers use it to fix poorly formatted data before database imports. Marketing teams use it to clean contact lists before campaigns. Operations staff use it to normalize supplier or inventory data that comes in from multiple sources in different formats. If you work with spreadsheets, you'll find a use for it.

Frequently asked questions

Is this CSV cleaner really free?

Yes, completely free with no sign-up required. Upload, clean, and download as many files as you need.

Is my data safe when I use this tool?

Absolutely. All processing happens directly in your browser using JavaScript. Your file is never uploaded to any server, so your data stays completely private.

What file formats does the Excel Cleaner support?

We support .csv, .xlsx (Excel 2007+), and .xls (older Excel format). Output can be downloaded as either CSV or XLSX.

How large a file can I clean?

Files up to 10MB work well for most spreadsheets. For very large datasets with hundreds of thousands of rows, performance depends on your device.

Can it handle spreadsheets with merged cells?

The tool works best with flat, tabular data. Merged cells in Excel files are typically unmerged during import, which may require some manual tidying for complex layouts.

What does 'normalize dates' actually do?

It converts common date formats like MM/DD/YYYY or DD-MM-YYYY into the ISO 8601 standard YYYY-MM-DD format, which is universally accepted by databases and most software.