Exploration prototype · free · not for sale · runs entirely in your browser, nothing is uploaded
Clean a messy contact list before you import it.
Contact lists from trade fairs, old CRMs and newsletter tools are full of “MÜLLER, ANNA”, gmial.com, phone numbers in five formats and the same person three times. This tool tidies them up and shows you, row by row, what it changed, what it merged and what it rejected.
Clean a listWhat it does not check →
Your file is read by this page in your browser. It is not uploaded, not stored and not sent anywhere.
Mustermann, ErikaErika Mustermannmax@mial.example.comtypo? mail.example.comrow 4duplicate of row 2Clean and check
What it does
- Names: “Müller, Anna” becomes “Anna Müller”; ALL CAPS and all-lowercase names get normal capitalisation (van, von, de stay lowercase).
- Emails: trims spaces, “mailto:” and brackets, lowercases, checks the syntax, flags disposable domains and role addresses such as info@ or sales@, and suggests a fix for likely typos of about 20 large providers (gmial.com → gmail.com) in a separate suggested_email column. It never rewrites an email.
- Phones and countries: phone numbers to international format (+49…) when the country is known; country names to two-letter codes (Deutschland → DE).
- Duplicates: rows with the same email, or without email the same name and the same company (both filled in), are merged into the first one. Empty fields of the first row are filled from the duplicate; in your other columns (notes, owner …) differing values of the duplicate are added to the first row, joined with “ | ”, and the page warns about them. The audit lists every merge.
- Accounting: every input row ends up as kept, merged, rejected (with the reason) or empty. The audit file has one line per input row with your original values; the cleaned list adds the values of merged duplicates to the kept row with “ | ”. In both, cells starting with =, +, - or @ get a leading apostrophe so they cannot run as formulas.
What it does not check
- No mailbox verification. A syntactically valid address can still bounce: nothing checks whether the mailbox exists.
- No SMTP or DNS check. No mail server is contacted and no MX record is looked up. This page makes no network requests with your data.
- No enrichment. Nothing is added from other sources: no job titles, no company data, no missing emails or phone numbers.
- No consent or legal check. Whether you may contact these people (GDPR, UWG, CAN-SPAM) is not checked.
- Typo suggestions can be wrong. A domain close to a large provider gets a suggestion (e.g. gmial.com → gmail.com), never an automatic change; known real domains such as yahoo.es or mail.com get none. Decide yourself whether to use the suggested_email column.
- Duplicates by exact email or name + company only. “Anna Müller” and “A. Mueller” are not recognised as the same person. Rows without an email and without both name and company are never merged.
- Phone numbers for nine countries. Local numbers are converted only for DE, AT, CH, US, GB, FR, NL, ES and IT; others need a + prefix.
- CSV only, up to 5 MB and 50,000 rows. Save Excel files as CSV UTF-8 first. A file with a quote character that is never closed is refused with the line number, rather than guessed.
Cells that a spreadsheet would run as a formula (starting with =, +, - or @) are written with a leading apostrophe in the downloads, so they show as text.
Excel may display phone numbers in +49 format as plain numbers and drop the +. To keep them, open the CSV via Data → From Text/CSV and set the phone columns to Text; CRM imports read them as they are.
Built by the 28/28 AI venture builder from a tested cleaning module; the browser version is held to the original by automated parity tests. Demand is not verified. An exploration prototype is a public test of the core function, not a product for sale.