Clean and tidy your contact lists
Remove duplicates, check emails, format phone numbers and split names for better outreach. It all runs in your browser: your file is never uploaded.
Remove Duplicates
Check Emails
Format Phones
Clean & Standardize
1. Upload Your Contact List
No file chosen yet
Your file stays on your device. Your browser reads it here and nothing is uploaded.
2. Cleaning Options
Select what you want to clean. Spaces, emails and phone formats are always tidied.
3. Results Summary
- –Valid Format
- –Invalid Emails
- –Role Addresses
- –Duplicates Removed
- –No Email
- Clean Contacts
- –
- Invalid Emails
- –
- Unrecognised Phones
- –
- Duplicates
- –
Cleaned Contacts Preview
Preview your cleaned contacts before downloading. The status columns show what was checked.
Your cleaned rows appear here
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How to clean a contact list
How do I clean up a contact list?
Remove the duplicate rows, trim and lowercase the email addresses, flag the ones that are badly written or go to shared inboxes like info@, put every phone number in one format and split full names into first and last. The cleaner above does all of it in your browser and shows what it changed before you download.
| Step | What it does |
|---|---|
| Spaces | Spaces at the start and end of every cell are removed, including the non-breaking spaces that come with text copied from web pages. Empty rows are dropped. |
| Emails | Lowercased, with mailto:, angle brackets and stray punctuation removed. A cell that holds two addresses keeps both. |
| Invalid emails | Marked “invalid” in a new Email status column when the address is not written correctly: no @, no domain ending such as .com, or two dots in a row. |
| Role addresses | Marked “role address” when the address is a shared inbox such as info@, sales@ or support@ rather than a person. |
| Phone numbers | Rewritten in the one format you pick. Numbers with no + code are read as the country you choose. A number that cannot be read is left exactly as it was and marked “not recognised”. |
| Names | A full-name column is split into First name and Last name. Titles such as Dr. and letters such as MD are dropped, Jr. stays with the last name, and “Smith, John” is read the right way round. In a business listing, where Name sits beside columns such as Category or Rating, Name is read as the company and not split. |
| Duplicates | Two rows are the same contact when their emails match. If either has no email, when their phones match and their names do not disagree; if neither has a phone, when name and city match. The first row is kept and its empty cells are filled from the copies. |
How the contact list cleaner works
- 1
Drop your list
A CSV or Excel (.xlsx) file. Your browser reads it on your device; nothing is sent anywhere.
- 2
Pick the settings
The phone format, the country for numbers without a + code, and whether to remove flagged rows or keep them marked.
- 3
Download the clean file
See how many rows went in and came out, how many duplicates were removed and what was flagged, then download CSV or Excel.
Contact list cleaning: questions
Is my file uploaded anywhere?
No. Your browser reads the file on your own device and does every step there. The file is not sent to LeadQuasar or to anyone else, and closing the tab discards it. The only things the page downloads are its own code.
How does it decide that two rows are duplicates?
By email first: two rows with the same email address, ignoring capitals and spaces, are one contact. When one of them has no email, it compares phone numbers after formatting them, and only if the names do not disagree, so two people sharing an office line stay two people. When there is no phone either, it compares name and city. It keeps the first row and fills its empty cells from the duplicates, so no detail is lost.
Does it check whether an email address really exists?
No. It checks that each address is written correctly and flags role inboxes such as info@ and sales@. Whether a mailbox exists can only be tested against the mail server. To check a single address, including whether its domain can receive mail at all, use the free Email Verifier.
Which phone formats can it produce?
International (+1 512 555 0100), E.164 (+15125550100, the format dialers and most CRMs store) or national ((512) 555-0100). Numbers written without a + code are read as the country you pick. Extensions are kept. Anything that cannot be read as a phone number is left as it was and flagged.
What happens to rows it cannot fix?
They stay in the file and are marked in the Email status or Phone status column, so you can sort or filter on them. If you would rather not have them, tick the options to remove rows with an invalid email or a role address before you download.
How big a file can it clean?
Up to 10 MB and 100,000 rows per file. A larger list can be split into parts and cleaned one part at a time.
Does it work with Excel and Google Sheets?
Yes for Excel .xlsx files: it reads the first sheet that has data, and you can pick another sheet. From Google Sheets, use File, then Download, then CSV or Microsoft Excel. Older .xls files need saving as .xlsx or .csv first.
Why do phone numbers look wrong when I open the CSV in Excel?
Excel reads a value such as +15125550100 as a number or a formula and drops the plus sign or shows an error. The file itself is fine and imports correctly into a CRM. To open it in Excel, use the Excel download instead: it stores phone numbers as text, exactly as written.
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