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Website & internet infrastructure inspector

Signalhouse

Inspect DNS, TLS, mail, CDN and routing of all your domains — and see what changed.

Launch Signalhouse → Tutorials

Signalhouse turns usefulweb’s network explorers into one inspection workspace. Add a portfolio of domains, pick a suite of checks — multi-region uptime and response headers, DNS and certificates, mail security, HTTP stack, CDN caching, IPv6, global DNS propagation, Certificate Transparency, domain history, BGP routing, outage signals, accessibility and AI readiness — and run them as a paced batch. A scorecard, merged findings with triage, run-to-run diffs, A/B comparisons and a renewal calendar turn the results into decisions; projects stay in your browser.

Free · runs in your browser · no sign-up · Version 1.0.0

Signalhouse overview with key figures and a scorecard of five mail providers across mail-security and DNS checks

Screenshots

Features

  • Domain portfolio

    Paste a domain list, a CSV with labels and tags, URLs or whole e-mails — Signalhouse extracts the host names, removes duplicates and explains every line it skipped.

  • Sixteen checks, one suite

    Uptime from several regions with security headers (HeaderLens), DNS & certificate, mail security, security headers, HTTP stack, CDN caching, IPv6, global DNS, Certificate Transparency, domain history, BGP routing, network neighbours, outage signals, accessibility, AI readiness and page changes — per project or per target.

  • Paced batch runner

    Runs hundreds of checks in the background within the API’s rate limit: live progress and time estimate, automatic waiting on “too many requests”, retry for failed checks, pause, and resume after you reconnect.

  • Scorecard dashboard

    Targets × checks in one matrix with grades, scores, days to certificate expiry and finding counts; one click opens the full result with metrics, facts and findings.

  • Merged findings & triage

    Every finding of every tool in one list, grouped across domains (“4 targets: DMARC policy is none”), with triage states (open, accepted risk, fixed, ignored) and notes that carry over to the next run.

  • Fix plan

    The concrete fixes the tools suggest — security headers, SPF, DMARC, MTA-STS, crawler access — deduplicated over all targets, as a checklist you can export.

  • Change history & baselines

    Every run is kept: compare any two runs or a pinned baseline and see which records, name servers, certificates, technologies, grades and findings appeared or went away.

  • A/B comparison

    Put two targets side by side — staging and production, before and after a migration, you and a competitor — with every differing fact highlighted.

  • Renewal calendar

    Certificate end dates, expiring names from Certificate Transparency and domain registration expiry on one timeline, exported as an .ics calendar with reminders and a re-run schedule.

  • DNS → BGP → network chain

    Routing checks take the address from the DNS result, the network check takes the origin AS from routing — so one run answers “who announces this site, and is that network having an outage?”.

  • Page change watch

    Compare a page with a pasted earlier version or with its last Internet Archive capture from the domain history, and get prices, terms, dates and links that changed, ranked.

  • Private and staging targets

    For hosts the server cannot reach, paste response headers, DNS records or HTML and run the same checks on them in paste mode.

  • Lab: phishing, browsers, outages, speed

    Check suspicious messages and turn their links into targets, keep a browser-support budget of Baseline features, watch countries and networks for outages and log your connection speed over time.

  • Reports & exports

    Printable report (PDF via print), CSV of the scorecard, findings and fix plan, JSON results, Markdown report, SVG/PNG charts and the App Bridge to other premium apps.

  • Local-first projects

    Autosave and recent projects in your browser, project files, share links, undo/redo, Google Drive (when signed in) and a project format documented as a JSON schema for scripts and AI agents.

Templates

Start from a ready-made project and change it to fit.

Built-in tools

Signalhouse uses these tools. Each one also has its own page and works on its own, in the browser, through the JSON API and through MCP.

For AI agents

Signalhouse runs on a deterministic engine. The same functions are available as tools with a JSON API and MCP, so scripts and AI agents get exactly the results the app shows.

  • HeaderLens – Is a website down? Multi-region status, redirects, TLS and security headers.
    Tool page · POST https://signalhouse.usefulweb.app/api/v1/tools/headerlens/calculate · MCP headerlens
  • DNS + Certificate Explorer – DNS records, e-mail security, CAA, live TLS certificate and CT history for a domain.
    Tool page · POST https://signalhouse.usefulweb.app/api/v1/tools/dns-certificate-explorer/calculate · MCP dns_certificate_explorer
  • E-mail Infrastructure Explorer – MX, SPF lookups, DMARC, DKIM, MTA-STS, TLS-RPT and BIMI for a domain, scored with fixes.
    Tool page · POST https://signalhouse.usefulweb.app/api/v1/tools/email-infrastructure-explorer/calculate · MCP email_infrastructure_explorer
  • Security Configuration Scanner – Passive, graded check of a domain's TLS, security headers, DNS security and security.txt.
    Tool page · POST https://signalhouse.usefulweb.app/api/v1/tools/security-configuration-scanner/calculate · MCP security_configuration_scanner
  • HTTP Technology Explorer – Headers, compression, caching, HTTP/2-3 hints, redirects, security and tech stack for a URL.
    Tool page · POST https://signalhouse.usefulweb.app/api/v1/tools/http-technology-explorer/calculate · MCP http_technology_explorer
  • CDN Behaviour Explorer – Which CDN serves a URL, whether it caches it (HIT/MISS, Age, TTL) and how, from two requests.
    Tool page · POST https://signalhouse.usefulweb.app/api/v1/tools/cdn-behavior-explorer/calculate · MCP cdn_behavior_explorer
  • IPv6 Readiness Explorer – Is a domain reachable over IPv6? Web, DNS and mail checks, address classes and a scored report.
    Tool page · POST https://signalhouse.usefulweb.app/api/v1/tools/ipv6-readiness-explorer/calculate · MCP ipv6_readiness_explorer
  • Global DNS Explorer – Ask every authoritative name server and public resolvers: records, propagation, DNSSEC, mistakes.
    Tool page · POST https://signalhouse.usefulweb.app/api/v1/tools/global-dns-explorer/calculate · MCP global_dns_explorer
  • Certificate Transparency Explorer – Every logged certificate for a domain: history, issuers, subdomains, wildcards and expiry.
    Tool page · POST https://signalhouse.usefulweb.app/api/v1/tools/certificate-transparency-explorer/calculate · MCP certificate_transparency_explorer
  • Domain History Graph – Registration, DNS, hosting networks, certificates and Wayback captures of a domain as a timeline.
    Tool page · POST https://signalhouse.usefulweb.app/api/v1/tools/domain-history-graph/calculate · MCP domain_history_graph
  • BGP Route Explorer – Who announces an IP or prefix in BGP: origin ASes, RPKI validity, visibility and origin changes.
    Tool page · POST https://signalhouse.usefulweb.app/api/v1/tools/bgp-route-explorer/calculate · MCP bgp_route_explorer
  • ASN Relationship Explorer – An autonomous system at a glance: holder, country, BGP neighbours and announced prefixes.
    Tool page · POST https://signalhouse.usefulweb.app/api/v1/tools/asn-relationship-explorer/calculate · MCP asn_relationship_explorer
  • Internet Outage Atlas – Correlate public outage signals (IODA, RIPEstat BGP, live probe) for a country, ASN or domain.
    Tool page · POST https://signalhouse.usefulweb.app/api/v1/tools/internet-outage-atlas/calculate · MCP internet_outage_atlas
  • AI Website Readiness Explorer – Can ChatGPT, Claude, Perplexity and AI agents read your website? Explainable score.
    Tool page · POST https://signalhouse.usefulweb.app/api/v1/tools/ai-website-readiness-explorer/calculate · MCP ai_website_readiness_explorer
  • Accessibility Snapshot – Static WCAG 2.2 snapshot of a page: findings by severity, evidence and manual checks.
    Tool page · POST https://signalhouse.usefulweb.app/api/v1/tools/a11y-snapshot/calculate · MCP a11y_snapshot
  • Website Change Explainer – Compare two versions of a page and see which changes matter: prices, terms, dates, links.
    Tool page · POST https://signalhouse.usefulweb.app/api/v1/tools/website-change-explainer/calculate · MCP website_change_explainer
  • Scam Signal Checker – Check a message or link for common scam and phishing warning signs — without clicking.
    Tool page · POST https://signalhouse.usefulweb.app/api/v1/tools/scam-signal-checker/calculate · MCP scam_signal_checker
  • Browser Compatibility Checker – Which browsers support a CSS property, JS API or HTML element? MDN data + Baseline status.
    Tool page · POST https://signalhouse.usefulweb.app/api/v1/tools/browser-compatibility-checker/calculate · MCP browser_compatibility_checker
  • Network Speed Tester – Measure latency, jitter, download and upload speed between your browser and our server.
    Tool page · POST https://signalhouse.usefulweb.app/api/v1/tools/network-speed-tester/calculate · MCP network_speed_tester
  • Explorer of Everything – Search transactions, contracts, domains, packages, advisories, MCP servers and websites in one box.
    Tool page · POST https://signalhouse.usefulweb.app/api/v1/tools/explore/calculate · MCP explore

Build a project through the API, then open it in the app with a link to https://signalhouse.usefulweb.app/app#project=<base64url JSON>.

Import & export

Import

  • Signalhouse project (.signalhouse.json)
  • Domain lists (one per line, CSV/TSV with a domain or URL column, free text with links)
  • Project link (#project=…)
  • App Bridge: text and tables with domains

Export

  • Signalhouse project (.signalhouse.json)
  • Printable report (PDF via print)
  • Markdown report
  • CSV: scorecard, findings, fix plan, changes, renewals
  • JSON results
  • iCalendar renewal calendar (.ics) with reminders
  • SVG and PNG of the scorecard, renewal timeline and connection log

Keyboard shortcuts

Keyboard shortcuts in Signalhouse
KeysAction
Ctrl + EnterRun the suite for all targets
Ctrl + Shift + EnterRun the selected target
Ctrl + Z / Ctrl + YUndo / redo
Ctrl + SSave project file
Ctrl + OOpen project file
Ctrl + PPrint report
Ctrl + DDuplicate the selected target
DeleteRemove the selected target (in the target list)
1 … 7Overview, Target, Findings, Changes, Compare, Renewals, Lab
NAdd targets
[ / ]Previous / next target
?Keyboard shortcuts

Frequently asked questions

Is Signalhouse free?

Yes. The workspace runs in your browser and stores projects locally in IndexedDB and in files you download. The checks call usefulweb’s public tools, which are free and rate-limited.

Where do the results come from?

Each check runs one usefulweb tool on the server — for example the DNS & Certificate Explorer, the Email Infrastructure Explorer or the BGP Route Explorer. They query public DNS, the site itself, Certificate Transparency (crt.sh), RDAP, the Internet Archive, RIPEstat and IODA. Signalhouse stores a compact summary of each result in your project.

Why does a large run take several minutes?

Network tools are limited to 15 calls per minute per visitor so the public sources stay usable for everyone. Signalhouse paces the queue, shows the remaining time and waits automatically when the limit is reached; you can keep working meanwhile.

Is it safe to inspect domains I do not own?

The checks are passive: DNS lookups, ordinary page requests and public databases, no port scans or probing. The security configuration scan still asks you to confirm that you own the domains or are authorised to test them before it runs live.

How are the statuses in the scorecard decided?

A check is red when a tool reports a high-severity finding, a grade of D or F, an invalid or expired certificate or an ongoing outage; amber for medium findings, grade C or a certificate within your warning window; green otherwise. Grades and scores themselves come from the tools.

Can I check internal or staging sites?

Only through paste mode: copy the response headers, DNS records or HTML into the target’s pasted inputs and the same tools analyse that text. Live checks always run from usefulweb’s server and cannot reach private networks.

Does Signalhouse monitor my domains around the clock?

No. Nothing runs while the page is closed. Set a re-run cadence and download the calendar: it reminds you when the next run is due and before certificates or registrations end; the Changes view then shows what moved since the last run.

Can an AI agent use it?

Yes. The project format is a documented JSON schema (/project.schema.json); an agent can create a project with targets and open it via a #project= link, and every check is also available directly through the API and MCP endpoints listed on this page.

Limitations

What Signalhouse does not do (yet):

  • No unattended monitoring: runs happen while the workspace is open; reminders come from the calendar export.
  • Network checks are rate-limited to about 15 per minute per visitor, so a run over 100 targets with 6 checks takes around 40 minutes.
  • Live checks run from one server location; CDN behaviour, DNS answers and reachability can differ elsewhere.
  • The accessibility snapshot reads the static HTML only; it cannot replace a manual audit with assistive technology.
  • Private networks and hosts behind a login can only be analysed from pasted headers, records or HTML.
  • Tool findings and summaries are shown in English when a translation is not available.
  • Projects keep a compact summary of each result, not the full raw tool output; open the tool page for every detail.

Tutorials

Learn Signalhouse step by step.

  1. Your first inspection in five minutesAdd a few domains, run the default suite, and read the scorecard, the key figures and the first findings. No account, nothing to install.Beginner 5 min
  2. Work through findings with triage and a fix planMerge the findings of every tool and domain into one list, decide what to fix, accept or ignore, and export a deduplicated fix plan.Beginner 7 min
  3. See what changed — runs, baselines and a DNS migrationEvery run is kept. Pin a baseline before a change, run again afterwards and read exactly which records, name servers, certificates and findings moved.Intermediate 8 min
  4. A renewal calendar for certificates and domainsCollect TLS certificate end dates, expiring names from Certificate Transparency and domain registration expiry, and export them as an .ics calendar with reminders.Beginner 5 min
  5. Is it us or the internet? Routing and outage signalsFollow a domain from its DNS answer to the BGP prefix, the origin network and its neighbours, and check public outage signals for the domain, countries and networks.Intermediate 8 min
  6. Triage a suspicious message and its lookalike domainsCheck an e-mail or SMS for scam signals without opening the links, then inspect the linked domains — age, certificates, DNS — as targets.Intermediate 6 min
  7. Check staging and private hosts with pasted inputsLive checks run from usefulweb's server and cannot reach private networks. Paste headers, DNS records or HTML instead and run the same analysis.Advanced 7 min
  8. Automate with the API, MCP and the project formatCall every check from scripts or AI agents, and hand a ready-made project to a person through a #project= link.Advanced 6 min

Ready to try it?

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