How It Works
Clean your UK data in 4 simple steps. Everything happens in your browser - your data never leaves your device.
Upload Your File
Upload your CSV, Excel (.xlsx, .xls), or JSON file containing UK phone numbers, National Insurance numbers, postcodes, bank sort codes, bank account numbers, or full names.
Tip: We support files up to several hundred MB, depending on your browser and device memory. All processing happens in your browser, so larger files may take a bit longer.
Select Columns to Clean
Choose which columns you want to clean. Our system can automatically detect phone numbers, NI numbers, postcodes, sort codes, bank account numbers, and full names, or you can manually select the columns.
Auto-Select: Click "Auto-Select" to have our system automatically detect and select all cleanable columns based on column names and content. For full name columns, it will also suggest name splitting.
Name Splitting: For full name columns, you can choose to split them into separate `title`, `first_name`, and `last_name` columns. The system automatically extracts titles (Mr, Mrs, Dr, etc.) and handles name suffixes (like Jr., Sr., II, III) that appear after the last name.
Phone Number Format: Choose between International format (+44) or UK format (0) for phone number output. This applies to all phone and mobile columns you select.
Protected Columns: ID and key columns (like customer_id, order_number) are automatically protected and will never be modified - preserving your data relationships.
Process in Your Browser
Click "Clean My Data" and watch as your data is validated and cleaned instantly - all in your browser. We never see, store, or transmit your data. It's 100% private.
Privacy First: Your file is processed entirely in your browser using JavaScript. No uploads to our servers, no database storage, no third-party access.
Data Insights: Get instant insights including missing values count, duplicate row detection, and data quality profiling before you download.
Comprehensive Reports: Access three detailed HTML reports: Full Preview (complete dataset with colour coding), Issues Report (invalid values with explanations), and Cleaned Report (all cleaned values with before/after). All reports persist on page refresh.
Download Your Cleaned Data
Review the complete cleaned dataset with our Full Preview feature, customise your download options, and export with confidence knowing exactly what you're getting.
Full Preview - See Everything Before Download:
- • View your complete cleaned dataset with all rows and columns
- • Blue rows = Original rows that have duplicates elsewhere
- • Yellow rows = Duplicate rows (removable via checkbox)
- • Green cells = Values that were cleaned or fixed
- • Red cells = Invalid values detected but cannot be cleaned (require manual correction)
- • Protected columns (IDs, keys) are marked and never modified
Select Your Download Format:
- • CSV - Comma Separated Values (great for spreadsheets)
- • Excel (.xlsx) - Native Excel format (ready to open in Excel)
- • JSON - Structured data format (perfect for developers)
Format Conversion: Upload in CSV? Download as Excel or JSON. Upload in Excel? Download as CSV or JSON. We support complete format conversion!
Export Customisation Options:
Remove Duplicate Rows
Automatically removes exact duplicate rows, keeping only the first occurrence. Duplicates are highlighted in the preview so you can review before removing.
Clean Whitespace
Trims leading/trailing spaces and normalizes multiple spaces to single spaces across all cells for consistent formatting.
Include "Issues" Column
Adds an "Issues" column that lists any fields that still need attention. This helps you quickly identify which rows may require manual review after downloading.
Export Only Rows With Issues (Optional)
When enabled, you'll download only the rows that have validation issues (instead of the complete cleaned file). Perfect for creating a focused review file that you can fix manually and merge back into your main dataset.
Important: Download and Save Your File
Your cleaned data is only available in your browser session. Once you close the browser tab or refresh the page, your cleaned data will be gone. We don't store files on our servers - make sure to download and save your cleaned file immediately after processing!
Key Features
100% Private
All processing happens in your browser. Your data never leaves your device.
GDPR Compliant
We're not a data processor - you maintain full control and compliance.
Format Conversion
Upload CSV, download Excel. Upload Excel, download JSON. We support format conversion.
Instant Processing
No upload wait times, no network bottlenecks. Process instantly in your browser.
Want More Details?
Check out our comprehensive documentation for detailed guides, visual examples, troubleshooting tips, and advanced features.
View Full Documentation