Clean duplicate contacts from a CSV — without uploading it

Paste or upload a messy CSV of contacts, map the name/email/phone columns, and find the duplicates — certain ones (same email or phone) and fuzzy ones (typos, nicknames, reordered names) alike. Nothing is merged automatically: every group is yours to review, pick a keeper, and decide.

How it works: an exact-match pass groups records with an identical normalized email or phone number. A separate fuzzy pass compares names with a real string-similarity algorithm (Levenshtein edit-distance plus token-based matching, so "Jon Smith" / "Jonathan Smith" and "Smith, Priya" / "Priya Smith" are both caught) at a sensitivity you control. Nothing is uploaded: this page makes no network requests at all.

How to use this tool

Use the dropzone below — that's the whole tool. (The downloaded version is the same tool as a file that opens in any browser, no install or internet needed.)
Paste your CSV into the text box, or click Choose a CSV file… to upload one. First row is treated as headers.
On the mapping screen, confirm which columns are Name (or First/Last), Email, and Phone — they're pre-guessed for you. Adjust the fuzzy-match sensitivity slider if you want (70% is a reasonable default).
Click Find duplicates. Certain (exact-match) and possible (fuzzy) groups are listed separately, each with every member's similarity score against the current keeper.
For each group: pick which record to Keep, then check Remove as duplicate on any others that are truly the same person. Leave genuinely different people unchecked — they'll both stay in your export.
Click Export cleaned CSV for the final file, with casing/whitespace normalized and a notes column documenting what happened to each row.

Load your contact list

CSV only, first row treated as headers. Everything happens in this tab — nothing is sent anywhere.

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What is this page?

This is the real Contact List Cleaner — the same tool Untracked sells as a download — running free, right here in your browser. Everything is processed entirely on your own device: nothing is uploaded, no account is needed, and the page makes no network requests after it loads. You can verify that yourself: load the page, open your browser's network inspector, or even disconnect from the internet and keep using it.

Questions people ask

Does my contact list get uploaded anywhere?

No. The dedupe runs entirely inside this page — no server, no account, no network calls. You can paste your CSV in with the Wi-Fi turned off.

Will it merge two different real people by mistake?

It never merges anyone automatically — that's the core safeguard. Fuzzy matches are flagged as "possible" and you review every single merge before anything changes.

How is this different from Excel's "Remove Duplicates"?

Excel only catches rows that are exactly identical. This tool normalizes emails and phone numbers for the exact pass, then runs real string-similarity matching on names — so typos like j.smith@ vs j.smith1@ or "Anna" vs "AnnA " get caught.

What file formats does it work with?

CSV — the export format of Gmail, Outlook, and Google Sheets. Paste it in or choose the file; the first row is treated as column headers.

What's the difference between this free page and the paid download?

This page processes one CSV at a time. The €9 download is the same cleaner as a single file — no limits, offline forever, for every future export.