Advanced Diagnostics

DNS Snapshot Diff & Migration Change Comparator

Compare DNS records across different points in time or between staging and production environments. Track added, modified, or deleted records during domain migrations and hosting provider changes. Taking a DNS snapshot before any major change and comparing it after is an essential safety practice — it prevents unintended record deletions that cause website outages or email delivery failures.

Key Capabilities & Features

dnsfyi combines high-speed global Anycast DNS queries with comprehensive security auditing into a unified diagnostic suite.

• Side-by-side visual diff of DNS record changes (added, modified, deleted)
• Snapshot export and import in standard JSON format
• Detection of modified TTLs, IP changes, and MX priority updates
• Essential migration safety tool to prevent DNS outages
• Multi-record type comparison (A, MX, TXT, NS, CNAME, CAA)
• Shareable diff report for team review

Frequently Asked Questions

Find direct answers about dnsfyi's multi-resolver query engine, privacy policy, domain security checks, and free REST API.

When should I use the DNS diff tool?: Use it before and after any DNS change: (1) Migrating web hosting to a new IP — compare A records before and after. (2) Switching email providers — compare MX and TXT (SPF) records. (3) Changing DNS providers — compare the complete zone. (4) After a security incident — detect unauthorized record changes.