host.tools
About v1.4.0 all systems operational

We took ten years of network-intelligence engineering
and built one home for it.

host.tools is a service by host.com and checkhost.com, partnering with data and services from hostinfo.com, hostcheck.com, crypt.tools, tokencalculator.com and marketcap.to. 80 tools, twelve global probe regions, one paste-anything smart input — built for the people who keep the internet running.

Browse 80 tools Read the API docs Talk to the team
80+
tools
12
probe regions
15
public DNS resolvers
8M+
lookups / month
~50ms
cached p50 latency
99.97%
uptime · 90 days
16+
RBLs in parallel
100/h
free API calls
Our mission

"Diagnostic tools should feel like a single fast home, not twenty browser tabs and three CLI installs. Public network metadata deserves a beautiful, modern UI — and a respectful, free API on top of it."

— host.tools founding principle, 2026
Trusted by teams at
Hacker News
Product Hunt
TechCrunch
The Register
Smashing Magazine
SitePoint
Powered by partners

Each tool is the best of several worlds.

We don't reinvent — we combine. host.tools stitches together the strongest data feeds and probe networks our family of products has been building for years.

host.com
Hosting infrastructure
checkhost.com
Multi-region probe network
hostinfo.com
GeoIP & ASN intelligence
hostcheck.com
Reputation & abuse data
crypt.tools
Cryptography utilities
marketcap.to
Market & economic feeds
tokencalculator.com
Token & API metering
ARIN / RIPE / APNIC
Direct port-43 RIR access
Architecture

How a request flows

No magic. Six clean layers, each cached, each replaceable.

1. Smart input

Auto-detect IP / IPv6 / CIDR / domain / URL / email / ASN / hash / UUID and route to the right tool with the right defaults.

2. Page cache

Redis-or-file public cache returns full HTML in under 5 ms on a HIT — no session, no dispatch, no tool execution.

3. Tool dispatch

ToolRegistry resolves the slug, applies rate-limit middleware, runs the tool class with strict timeouts.

4. Probes

DNS / HTTP / TCP / TLS / WHOIS / ICMP / SMTP — uniform envelope, mockable, no copy-pasted error handling.

5. Multi-region fan-out

For live tools: NodeService fan-outs over curl_multi to the probe fleet, streams results via Server-Sent Events.

6. JSON + view

Same payload powers /api/v1 and the web view — the HTML is just a renderer of the API response.

The team

Operators, not just engineers.

A small senior team that's been running production networks for a decade. We carry pagers, write the code, and answer the support channel.

🟦
Founder · CEO
host.com background
🟪
Founder · CTO
checkhost.com background
🟩
Head of Engineering
ex-CDN, ex-large hoster
🟧
Head of Design
ex-fintech, ex-consumer
🟥
Head of SRE
ex-payments, ex-DNS provider
🟫
Head of Customer
ex-developer-tools

We're hiring backend engineers, SREs, and a developer-relations lead.

See open positions
Values

What we believe

Speed is a feature

A tool you wait 3s for is broken. Cache aggressively, stream progress for slow probes, prefetch nothing the user didn't ask for.

Defaults beat options

Every tool one-clicks. Advanced dials live in a disclosure for the 5% who want them, but the 95% never see them.

Public data deserves nice UIs

DNS, WHOIS, certs and headers are public. The bar for the UI showing them should still be high.

Privacy by default

No tracking cookies. No data sales. Cached results are content-addressed; rate-limit IPs are hashed and rotated.

API-first

Every web view is a renderer of the same API payload. Whatever you see, you can script.

Honest about ETAs

If a probe is slow, we show the timer. If a region is offline, we say so. No fake green dots.

Boring tech, deeply understood

PHP, Redis, file caches, curl_multi. Not because it's old — because it works and we know every failure mode.

Real humans answer

Pro+ inquiries get a real person within 4 hours. Always. Email-only AI bots are a tax we won't levy.

Roadmap

What's next

  1. shipped

    Full-page cache + 9 new tools

    Redis-or-file page cache, expanded tool catalogue, sticky ad slots, SEO instrumentation.

  2. shipped

    Multi-region probe fleet + SSE

    Live ping/HTTP/TCP/UDP/DNS-propagation streaming from 12 regions.

  3. active

    Monitors GA

    Schedule any tool, diff results, alert via webhook / Slack / PagerDuty.

  4. planned

    On-prem appliance

    Self-hosted + connector to our managed probe network. Fully air-gapped option.

  5. planned

    Bulk API, exports, history

    Pro tier — 1k inputs/job, CSV/NDJSON/Excel, 90-day result history.

  6. planned

    Native mobile apps

    iOS + Android with notification-channel monitors.

  7. exploring

    Browser extension

    Right-click any element to inspect DNS/SSL/headers.

In the wild

What people say

“

"Replaced four bookmarks with one paste. The smart-input router is the killer feature."

CTO · devops shop, Berlin
“

"The multi-region propagation check is faster and clearer than dnschecker.org."

SRE Lead · fintech, NYC
“

"We use the API to wire SSL-expiry alerts into our PagerDuty. Zero noise, zero misses."

Head of Eng · SaaS, London
“

"Best modern interface I've seen for inspecting cookies and CORS. Bookmarked."

Frontend Dev · agency, Paris
“

"Email-auth all-in-one saved an afternoon of bouncing between MXToolBox tabs."

Deliverability lead · ESP, Tel Aviv
“

"Subdomain enumerator via CT logs is the cleanest UI I've used. Faster than crt.sh."

AppSec · pen-test firm, Toronto
Community

Where we hang out

GitHub
4.2k stars
Discord
1.8k members
Twitter / X
12k followers
YouTube
40+ tutorials
FAQ

Common questions

Is host.tools free?
Yes — every tool is free on the web with a generous rate limit (200/hour per IP). The API is free up to 100 calls/hour. Pro and Enterprise tiers add bulk lookups, monitors, alerts, history and 10k–100k+ daily API calls.
Can I use this commercially?
Yes. The free tier covers commercial diagnostic use. For embedding, white-labelling or running our tools inside private networks, see Pricing or talk to us.
Where do the probe nodes run?
Our default fleet currently includes 12 regions (US-East, US-West, Germany, UK, France, Netherlands, Singapore, Japan, Brazil, Australia, India, South Africa) plus a local node for offline dev. Enterprise customers can add private nodes inside their VPCs.
How fresh is the data?
Live probes are real-time. DNS, WHOIS, SSL and HTTP results are cached 5 minutes by default; pass ?nocache=1 for a forced refresh. GeoIP/ASN data is updated daily from hostinfo.com.
Do you store my queries?
Inputs and outputs sit in the cache for at most 1 hour. We don't share them with ad networks; we don't build cross-site profiles. See Privacy.
Can I self-host?
Enterprise customers get a packaged on-prem build with our 12-region probe network as a managed service. Contact us.
What happens if a probe times out?
NodeService marks that region offline for the run and reports it in the UI. Other regions still return.
How do I report abuse?
Email [email protected] with the timestamp and target. We log every request and cooperate with responsible-disclosure and law-enforcement requests where lawful.
Is there a free trial of Pro?
Yes — Pro is free for 14 days, no credit card required. See pricing.
Do you have a status page?
Yes — /status shows fleet health, recent incidents, latency tiles. Subscribe at [email protected] for incident emails.

Ready to inspect anything?

Press ⌘K from any page to open the command palette. Or paste a domain, IP or URL on the homepage.

Open the homepage Get an API key Talk to us