Mapping online identities

Connect aliases, breached data, and behavioural markers across platforms.

12 min read
Intermediate
Overview

Identity mapping is the process of connecting disparate pieces of information to build a comprehensive profile of an individual or entity online. This involves correlating usernames, email addresses, phone numbers, and behavioral patterns across multiple platforms.

This tutorial will teach you how to pivot from a single data point (like a username or email) to discover associated accounts, leaked credentials, and patterns of behavior that reveal a person's digital footprint.

You'll learn privacy-respecting investigative techniques used by journalists, researchers, and security professionals to understand online identities.

Tools You'll Need

Sherlock

Username Search

Hunt down social media accounts by username across 300+ platforms

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Holehe

Email Analysis

Check if an email is used on different sites like Twitter, Instagram, etc.

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Hunter.io

Email Analysis

Find email addresses and verify email patterns

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Have I Been Pwned

Data Breach Search

Check if email addresses appear in known data breaches

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Maltego

Data Visualisation

Map relationships between identities, domains, and infrastructure

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Step-by-Step Guide
  1. 1

    Start with a single identifier (username, email, phone number, or name)

  2. 2

    Search for the username across social media platforms using automated tools

  3. 3

    Check if the email appears in data breaches or on compromised credentials databases

  4. 4

    Identify connected email addresses through password reset flows (ethically)

  5. 5

    Look for username reuse patterns and variations across platforms

  6. 6

    Analyze profile pictures using reverse image search

  7. 7

    Document behavioral patterns (writing style, interests, timezone activity)

  8. 8

    Map all findings in a visual graph to identify connections and overlaps

  9. 9

    Cross-reference information to verify accuracy and avoid false positives

Tips & Best Practices
  • Start broad with username searches, then narrow down to confirmed accounts

  • Look for consistent patterns: same profile picture, bio format, or interests

  • Check for numbered variations of usernames (e.g., john_doe, john_doe1, john_doe23)

  • Use Wayback Machine to see historical profile information

  • Pay attention to unique identifiers like custom URLs or specific phrases

  • Always verify connections through multiple data points

  • Respect privacy laws and ethical boundaries in your investigations

  • Document your methodology and sources for transparency

  • Be aware of false positives - common usernames may belong to different people

  • Use data breach information responsibly and ethically

Community Tips & Insights

Share your own tips or learn from the community's experience

Share Your Tip

OSINTExpert9/25/2025

I've found that combining multiple reverse image search engines in parallel significantly improves results. Don't rely on just one!

CyberSleuth9/28/2025

Always document your methodology step-by-step. This helps with reproducibility and explaining your findings to others.