adr

.adrAddress Book

Various (VCF standard) · 1996

Developer
Various (VCF standard)
Category
Documents
MIME Type
text/x-vcard
First Released
1996
Open Format
Yes
File Signature
Not consistently defined as a unique header; typically relies on text tags like 'BEGIN:VCARD' and 'END:VCARD'.
At a Glance
.adr
Address Book

An ADR file is a digital contact card format used to store and share personal or business contact information like names, phone numbers, and addresses.

Reviewed on June 5, 2026
Compression
Plain text
Transparency
No
Editability
High
Best for
Contact information exchange

Key Features

  • Stores comprehensive contact details (name, phone, email, address, etc.).
  • Plain text format, easily editable with basic text editors.
  • Standardized vCard (VCF) compatibility for cross-platform use.
  • Can be imported/exported between various contact management applications and devices.

Best For

  • Exchanging contact information between different apps and devices.
  • Storing detailed contact profiles.
  • Archiving your contact lists.
  • Creating portable contact backups.

Less Ideal For

  • Storing multimedia files like photos or videos.
  • Complex data relationships beyond contact information.
  • Rich text formatting or styling within contact entries.
  • Securely encrypted contact storage without additional measures.

Common Use Cases

  • Exporting contacts from an old phone or software.
  • Sharing contact details with others.
  • Creating backups of your contact list.
  • Importing contacts into new devices or applications.
  • Managing business contact information.

How to Open It

  1. Double-click the file; your operating system might automatically open it with a default contact application (like Windows Contacts or macOS Contacts).
  2. Open your preferred contact management software (e.g., Microsoft Outlook, Google Contacts, Apple Contacts) and use its import function, selecting the ADR/VCF file.
  3. Open the file in a plain text editor (like Notepad on Windows or TextEdit on macOS) to view the raw contact data.

What is a .adr file?

An ADR file, often associated with the .vcf (vCard) format, is a plain text file designed to store contact information. This includes details like names, phone numbers, email addresses, physical addresses, and sometimes even company affiliations or job titles. It's a standardized format, meaning contact information can be easily shared and imported across different applications and devices. Think of it as a digital business card that can hold more data than a physical one and can travel with you anywhere.

Programs That Open .adr Files

PlatformProgram
WindowsMicrosoft OutlookPaidOfficial
Windows ContactsFreeOfficial
NotepadFreeOfficial
macOSApple ContactsFreeOfficial
TextEditFreeOfficial
LinuxEvolutionFree
ThunderbirdFree
AndroidGoogle ContactsFreeOfficial
Contacts+ (Third-party apps)Free
iOSApple ContactsFreeOfficial
Web BrowserGoogle ContactsFreeOfficial
Outlook.com ContactsFreeOfficial

How to Convert .adr Files

FormatMethod
.CSVExport from contact manager, Online converters
.JSONProgramming scripts, Online converters

Common Problems with .adr Files

⚠️ File not opening correctly.
Ensure you are using a compatible contact management application and check if the file is a standard VCF/ADR format. Corrupted files may need to be recreated.
⚠️ Encoding issues displaying special characters.
When opening in a text editor, ensure you select the correct character encoding (often UTF-8). Most modern applications handle this automatically.

Frequently Asked Questions

What is the difference between .adr and .vcf?

Often, there is no significant difference. '.adr' is sometimes used as an extension for files containing address book information, but they are almost always structured as '.vcf' (vCard) files, which is the industry standard.

Can I store photos in an ADR file?

Standard vCard (ADR) files are designed for text-based contact information. While some advanced implementations or proprietary versions might support embedding limited image data (like a small photo icon), it's not a primary or universally supported feature.

Is an ADR file secure?

As a plain text file, an ADR file is not inherently secure. Anyone with access to the file can read its contents. For sensitive contact information, consider storing it within a secure application or encrypting the file itself.

Technical Details

ADR files are typically plain text files adhering to the vCard (VCF) standard, which is managed by the Internet Mail Consortium. Each piece of contact information is represented by a specific tag (e.g., N: for name, TEL: for telephone) on a new line. The format is human-readable and can be easily parsed by software.

Did You Know?

The vCard format, which ADR files usually follow, was first published in 1996.
vCards can be digitally signed, allowing recipients to verify the sender's identity.

Security Information

ADR files are plain text and contain contact details. Treat them with the same caution as you would a business card or a contact entry in your phone. Avoid opening ADR files from unknown or untrusted sources, as they could potentially lead to phishing attempts or social engineering if the contact information itself is malicious.