Browser Migration Tool

Migrate browsing data between DIA, ChatGPT Atlas, and Brave Browser (or between any Chromium-based browsers).

Automatically detects the active browser profile - no need to know the user profile path!

Features

Supported Data Types

• Browser History - URLs, visit counts, timestamps
• Search History - All keyword searches from the address bar
• Cookies - Login sessions, preferences, etc.
• Visits - Individual page visits with timing data

Usage

1. Close Both Browsers

IMPORTANT: Always close both source and target browsers before running the migration to avoid database locks.

2. Run the Migration Tool

python3 ~/browser_migration.py

3. Select Browsers

The tool will ask you to select:

• Source browser (where to export from)

  • 1 = DIA (automatically detects active profile)
  • 2 = ChatGPT Atlas (automatically detects active profile)
  • 3 = Brave Browser (select by profile name, e.g. "Work")
  • 4 = Custom path

• Target browser (where to import to)

  • 1 = DIA (automatically detects active profile)
  • 2 = ChatGPT Atlas (automatically detects active profile)
  • 3 = Brave Browser (select by profile name, e.g. "Work")
  • 4 = Custom path

Note: The script automatically detects which profile is active by reading the browser's Local State file. For Brave, you can specify a profile by display name (e.g. "Work", "Personal") — leave blank to use the last-used profile.

4. Choose Migration Options

Option 1: Export source browser history to JSON

• Exports all URLs, visits, and search terms to ~/browser_history_export.json

Option 2: Export source browser cookies to JSON

• Exports all cookies to ~/browser_cookies_export.json

Option 3: Import history from JSON to target browser

• Merges exported history into target browser
• Handles duplicates automatically
• Updates visit counts

Option 4: Import cookies from JSON to target browser

• Merges exported cookies into target browser
• Skips duplicates

Option 5: Direct copy history (fast method)

• Directly merges databases without JSON export
• Faster but less flexible
• Both browsers MUST be closed

Option 6: List bookmarks

• View bookmarks from both browsers

Option 7: Full migration (recommended)

• Runs export + import automatically
• Migrates history, search terms, and cookies

Option 8: View sample data from source browser

• Preview recent URLs, search terms, and statistics
• Useful for verifying data before migration

Examples

DIA to Atlas

Source: 1 (DIA)
Target: 2 (Atlas)
Choice: 7 (Full migration)

DIA to Brave (specific profile)

Source: 1 (DIA)
Target: 3 (Brave)
Brave profile name: Work
Choice: 7 (Full migration)

DIA to DIA

Source: 1 (DIA)
Target: 1 (DIA)
Choice: 7 (Full migration)

Preview Before Migrating

Source: 1 (DIA)
Target: 3 (Brave)
Brave profile name: Work
Choice: 8 (View sample data)
Choice: 7 (Full migration)

Safety Features

• Automatic Backups: Creates timestamped backups before any modification

  • Format: History.backup_YYYYMMDD_HHMMSS
  • Saved in the same directory as the original database

• Duplicate Detection: Won't create duplicate entries

  • URLs are checked before importing
  • Cookies are checked by host_key + name + path
  • Search terms are checked by url_id + term

• Non-Destructive: Never deletes existing data

  • Only adds new entries or updates visit counts
  • Preserves all existing browser data

Exported JSON Format

History Export

{
  "export_date": "2025-11-21T...",
  "source": "/Users/.../Dia/User Data/Default",
  "urls": [...],
  "visits": [...],
  "search_terms": [...]
}

Cookies Export

{
  "export_date": "2025-11-21T...",
  "source": "/Users/.../Dia/User Data/Default",
  "cookies": [...]
}

Troubleshooting

"Database is locked" Error

• Close both browsers completely
• Check Activity Monitor for any browser processes
• Wait a few seconds and try again

"Database not found" Error

• Verify the browser is installed
• Check that you've run the browser at least once
• Try using option 3 (custom path) with the full path

Import Shows 0 New URLs

• Data might already exist in target browser
• Check duplicate URLs using option 8 (view sample data)
• This is normal if you've run the migration before

Technical Details

DIA, Atlas, and Brave all use Chromium's SQLite database format:

• History database: SQLite with tables for urls, visits, keyword_search_terms
• Cookies database: SQLite with encrypted_value field (empty for imported cookies)
• Timestamps: Chromium epoch (microseconds since 1601-01-01)

Automatic Profile Detection

The script intelligently detects the active browser profile:

For DIA:

• Reads Local State to find profile.last_used
• Falls back to Default profile

For Atlas:

1. Reads Local State file to find profile.last_used
2. If not found, uses the most recently modified user-* profile
3. Falls back to Default as last resort

For Brave:

1. Reads Local State's profile.info_cache to match a profile by display name
2. If no name given, falls back to profile.last_used
3. Falls back to Default as last resort

Brave profile data is located at: ~/Library/Application Support/BraveSoftware/Brave-Browser/

Notes

• Search history is stored in the keyword_search_terms table
• Cookie encryption is browser-specific (imported cookies won't have encrypted values)
• Visit timestamps are preserved exactly
• Both browsers must be closed for safe migration