vCard Checker — Fix a .vcf Contacts File Before Import

Why won't this contacts file import cleanly?

Paste or drop a .vcf (vCard) file and get every problem with its line number before Google Contacts, Apple Contacts or Outlook skips a contact or shows it blank: cards with no FN or N, bad emails and phone numbers, impossible birthdays, quoted-printable text, unclosed cards, duplicate UIDs and identical duplicate cards. Then download a copy with every provable fix applied.

The file is read in this browser tab and never leaves your device. This checks the file against the vCard standards, not against any one app. Independent of every contacts product named.

1. Your contacts file

A .vcf export from a phone, an address book, a CRM or a script.

Choose a file …or paste the text

Choose a file or paste the text, then click Check contacts.

The rules, and what they leave out

Structure: every BEGIN:VCARD closed by END:VCARD, VERSION (2.1, 3.0 or 4.0) first in each card, nothing outside a card.
Names: FN required in 3.0 and 4.0; N required in 3.0 and 2.1, with its five components (Family;Given;Additional;Prefix;Suffix).
Values: EMAIL looks like an address (no mailto:, no spaces), TEL has digits and a plausible length, BDAY and ANNIVERSARY are real dates.
Encoding: quoted-printable is a 2.1 encoding and is flagged in 3.0 and 4.0 cards; CHARSET is flagged in 4.0.
Duplicates: repeated UIDs, repeated email addresses across cards, and byte-identical cards.
Fixed automatically: a missing FN built from N, N padded to five components, identical duplicate cards dropped, lines refolded at 75 octets, CRLF line endings.
Never guessed: which version a card with no VERSION is, how to merge near-duplicate contacts, how to decode quoted-printable text.
Not checked: whether a given app will accept the file, that an address or number is real, embedded photos, vendor X- extensions. Read from memory of RFC 6350 and RFC 2426; confirm against the current standards.

Common questions

Why do contacts show up blank or missing after importing a .vcf file?

The usual causes are a card with no FN (formatted name), which vCard 3.0 and 4.0 require, a card with no END:VCARD so the next card is swallowed, a missing or wrong VERSION line, and two cards sharing a UID so one overwrites the other. This tool reports each with its line number.

Why do accented characters look like =C3=A9 after import?

That is quoted-printable, an encoding from vCard 2.1. A 3.0 or 4.0 reader does not decode it and shows the raw codes. The tool flags it; it does not decode it for you because that needs the card's character set.

Can it remove duplicate contacts?

It removes a card only when every property is identical to an earlier card, ignoring REV and PRODID. Near-duplicates (same email, different spelling) are reported, never merged, because which details to keep cannot be proven.

What does the fixed file change?

Only things it can prove: builds a missing FN from N, pads N to its five components, drops byte-identical duplicate cards, refolds lines to 75 octets and writes CRLF line endings. Everything else is left exactly as it was and listed as a finding.

Is my contact list uploaded anywhere?

No. The page reads the file in your browser and a test in the code asserts there are no network calls.

What does this not check?

Whether a particular app will accept the file, that an email address or phone number is real or reachable, embedded photos, or vendor extension properties (X- fields).