Tools API

Free public website checking tools. This page lists all 4 endpoints in the Tools area of the Visual Sentinel REST API.

Base URL: https://visualsentinel.com. Unless an endpoint says otherwise it accepts an API key or a session cookie, see Authentication. Most error responses use the ErrorResponse shape, see Errors and Rate limits.

Endpoints

Website health check: GET /api/tools/website-check
SSL certificate check: GET /api/tools/ssl-check
DNS lookup tool: GET /api/tools/dns-check
Website speed test: GET /api/tools/speed-test

Website health check

GET /api/tools/website-check

Free tool to check whether a website responds, from each check region, with its response time and certificate. Rate limited to 10 requests/minute per IP. With visual=1 it also tries one homepage screenshot (3 per 10 minutes per IP).

Authentication: no session or API key needed.

Parameters

url (query, string, required): URL to check (https:// prefix added if missing)
visual (query, string, optional): Also capture one homepage screenshot (the address is reduced to its origin). One of: 1.

Responses

200: Website check results. Body: object.
400: The address cannot be checked: missing, not a valid URL, or not a public http/https address. Body: object.
422: The site could not be checked: its name does not resolve (not_found, with lookup and an optional suggestion), or its bot protection blocked the check in every region, answering each with a verification page (bot_protection). Body: object.
429: Rate limit exceeded. Retry-After gives the seconds to wait. Body: object.
503: Our checker could not finish this check (check_error). Nothing is known about the site. Body: object.

Field	Type	Required	Description
`url`	string	No
`status`	string	No	One of: `UP`, `DEGRADED`, `DOWN`.
`responseTime`	integer or null	No
`statusCode`	integer or null	No
`sslValid`	boolean or null	No
`sslDaysRemaining`	integer or null	No
`sslIssuer`	string or null	No
`dnsTime`	integer or null	No
`regions`	array of object	No
`regions[].region`	string	No
`regions[].status`	string	No	One of: `UP`, `DOWN`.
`regions[].responseTime`	integer or null	No
`regions[].statusCode`	integer or null	No
`regions[].error`	string or null	No
`checkedAt`	string (date-time)	No
`screenshot`	string or null	No	visual=1 only: a data URL, or null when no screenshot was taken.
`screenshotUnavailable`	boolean	No	visual=1 only: screenshots are switched off for now.
`screenshotBlocked`	string	No	visual=1 only: the site's bot protection showed a verification page instead of the site. One of: `bot_protection`.
`screenshotLimited`	boolean	No	visual=1 only: this caller reached the screenshot limit.

SSL certificate check

GET /api/tools/ssl-check

Free tool to check SSL certificate validity, expiration, and chain details.

Authentication: no session or API key needed.

Parameters

domain (query, string, required): Host name, optionally with an https:// prefix or a :port, for example example.com or example.com:8443.

Responses

200: SSL certificate details.
429: Rate limit exceeded.

DNS lookup tool

GET /api/tools/dns-check

Free tool to check DNS records (A, AAAA, MX, NS, TXT, CNAME, SOA).

Authentication: no session or API key needed.

Parameters

domain (query, string, required)
type (query, string, optional): Record type. Case-insensitive. One of: A, AAAA, MX, CNAME, TXT, NS, SOA, ALL. Default: ALL.

Responses

200: DNS records.
429: Rate limit exceeded.

Website speed test

GET /api/tools/speed-test

Free tool to test website loading speed and performance metrics.

Authentication: no session or API key needed.

Parameters

url (query, string, required)

Responses

200: Speed test results.
429: Rate limit exceeded.
503: The test did not run. SPEED_TEST_SERVICE_BUSY: the testing service was busy, rate limited or timed out (not a problem with the page); a Retry-After header is sent, try again in a few minutes. PAGE_NOT_TESTABLE: the page could not be loaded for testing. SPEED_TEST_UNAVAILABLE and SPEED_TEST_FAILED: the speed test is unavailable on our side. Failures are sent with Cache-Control: no-store.

Generated from the OpenAPI 3.1 specification at https://docs.visualsentinel.com/openapi.json, the same file the interactive reference reads.