MxToolbox alternatives for DNS-focused developers
What MxToolbox does
MxToolbox is a long-running network diagnostics platform that grew up around email delivery. Its core tools, MX lookup, blacklist checker, SMTP test, and deliverability monitor, serve sysadmins troubleshooting mail servers. Over the years it added DNS lookup, SPF/DKIM/DMARC checks, and HTTP diagnostics. For teams running their own mail infrastructure, it covers a lot of ground from one URL.
The tradeoff: the interface is dense, the free tier shows ads, and the advanced monitoring features are paid. If you need the email diagnostics side, that's often worth it. If you mostly want to look up DNS records or run a bulk WHOIS query, you're navigating around a lot of tooling that isn't relevant to you.
Why developers look for MxToolbox alternatives
- DNS without email baggage.Most DNS lookup tasks, checking A records after a deploy, verifying NS delegation, auditing a domain, don't need SMTP testing or blacklist monitoring. A dedicated DNS tool is faster to reach and less cluttered.
- Bulk operations.MxToolbox doesn't have a bulk DNS lookup path. When you need to query 50 or 200 domains at once, migration audit, DNS health sweep, domain portfolio check, you need something purpose-built for batch work.
- WHOIS with RDAP.MxToolbox's WHOIS is basic. If you need structured RDAP data for domains, IPs, and ASNs, especially in bulk, it's not designed for that.
- No ads, no account.Some developers just want to look something up without signing in or navigating around upsells.
DNS Buddy vs MxToolbox: feature comparison
| Feature | DNS Buddy | MxToolbox |
|---|---|---|
| DNS lookup (all record types) | ✓ | ✓ |
| Multiple DNS resolvers (Google, Cloudflare, Quad9, OpenDNS) | ✓ | Partial |
| WHOIS / RDAP lookup | ✓ | Limited |
| IP WHOIS + ASN lookup | ✓ | — |
| SPF record analysis | ✓ | ✓ |
| Bulk DNS lookup (up to 256 domains) | ✓ | — |
| Bulk WHOIS (domains, IPs, ASNs) | ✓ | — |
| Subdomain finder | ✓ | — |
| Reverse DNS (PTR) lookup | ✓ | ✓ |
| Subnet calculator | ✓ | — |
| Email blacklist monitoring | — | ✓ (paid) |
| SMTP connection test | — | ✓ |
| Email deliverability / inbox placement | — | ✓ (paid) |
| Account required | No | No (free tier) |
| API access | — | ✓ (paid plans) |
What DNS Buddy covers
DNS Buddy is a free toolkit for DNS research, domain analysis, and WHOIS queries. No account required for any tool.
Where MxToolbox is still the better tool
DNS Buddy is a DNS and WHOIS research tool. It doesn't do everything MxToolbox does, and these are real gaps, not things you'd discover after switching:
MxToolbox monitors your sending domain against 100+ blacklists and alerts you when you get listed. DNS Buddy has no continuous monitoring, it's single-shot lookups only. If deliverability monitoring matters to you, MxToolbox (or a dedicated deliverability tool) is the right call.
MxToolbox can actually connect to your mail server and test the SMTP handshake. DNS Buddy doesn't test SMTP. If you're debugging a mail server that's accepting connections but behaving oddly, MxToolbox's SMTP test is the right tool.
MxToolbox's paid tiers include inbox placement testing, sending actual test emails and checking where they land across major providers. DNS Buddy doesn't send email and has no deliverability scoring.
Other MxToolbox alternatives worth knowing
DNS Buddy isn't the only option. Depending on your actual use case:
Clean UI for single-domain DNS lookups across multiple resolvers. No WHOIS or bulk support.
Multi-location DNS propagation checker. Best when you need a visual global map of where a change has propagated.
Purpose-built propagation checker. Simple, fast, no frills, does one thing well.
Frequently asked questions
Is DNS Buddy free?
Yes. All tools, DNS lookup, WHOIS, SPF analyzer, subdomain finder, bulk DNS lookup, and more, are free with no account required.
Does DNS Buddy replace MxToolbox completely?
For DNS lookups, WHOIS queries, and SPF record analysis, yes. For email deliverability testing, SMTP diagnostics, blacklist monitoring, or inbox placement checks, no, those are MxToolbox specialties that DNS Buddy doesn't cover.
What can MxToolbox do that DNS Buddy can't?
MxToolbox offers SMTP connection testing, email blacklist monitoring with alerting, deliverability scoring, and inbox placement checks. DNS Buddy is a DNS and WHOIS research tool — it doesn't test SMTP connections or monitor deliverability over time.
Try DNS Buddy
All tools are free, no account needed. Start with the DNS lookup tool or check your SPF records.