API Monitoring Tools

Your API returned 500. Do you know?

UptimeSignal monitors your REST APIs from outside your infrastructure.
When an endpoint fails, you get alerted in under 2 minutes. Not when users complain.

25 monitors free. No credit card required.

uptimesignal — api checks

GET  api.yourapp.com/v1/health    200 OK   (89ms)
POST api.yourapp.com/v1/auth      200 OK   (124ms)
GET  api.yourapp.com/v1/payments  500 ERR  (2340ms)
  → Alert sent to [email protected]

1 min

Check interval

GET/POST

HTTP methods

<2 min

Alert delivery

Your API is the product.
If it's down, you're down.

Modern applications are built on APIs. Your mobile app talks to your backend. Your SaaS customers integrate via your public API. Your microservices call each other constantly.

When an API fails, everything downstream breaks. A 500 error on your payment endpoint means lost revenue. A timeout on your auth API means frustrated users who can't log in.

You need to know the moment an API fails — before your customers start complaining, before you lose transactions, before it cascades.

See all your APIs at a glance

Status, response times, uptime history. One dashboard.

UptimeSignal Dashboard showing API monitors with status indicators, response times, and uptime bars

What we check

Instant alerts everywhere

Email, Slack, Discord, Telegram, and webhook alerts within 60 seconds of detecting API failures. Recovery alerts when you're back online.

HTTP status codes

Detect 4xx and 5xx errors before your users do.

Response times

Catch slowdowns before they become outages.

SSL certificates

Get warned before your SSL expires.

Connection errors

DNS failures, refused connections, network issues.

Timeouts

Endpoints that hang without responding.

Custom headers

Auth tokens, API keys, custom request headers.

What to monitor

1

Health endpoints

Your /health or /api/status endpoint that checks database, cache, and critical dependencies.
2

Critical API routes

Authentication, payments, checkout — the endpoints that directly impact revenue.
3

Third-party dependencies

Stripe, Twilio, SendGrid — know when external APIs your app depends on go down.
4

Webhook receivers

Endpoints that receive callbacks from payment processors, messaging services, etc.
5

Microservices

Each service in your architecture that exposes an API.

How it works

Add your API endpoints

URL: https://api.yourapp.com/v1/health

Method: GET

Headers: Authorization: Bearer ...

We check every minute

✓ 10:01 — 200 OK (89ms)

✓ 10:02 — 200 OK (94ms)

✓ 10:03 — 200 OK (91ms)

Get alerted when it fails

✗ api.yourapp.com/v1/health — 500 Error

Email in your inbox. Slack ping in your channel. Within 2 minutes.

Simple pricing

No per-endpoint fees. Unlimited monitors for $15/month.

Free

Get started with essentials

25 API monitors
5-minute checks
Unlimited status pages
All integrations
Commercial use OK

Start free

$15 /month

For serious API monitoring

Unlimited monitors
1-minute checks
Unlimited status pages
All integrations
90-day history

Start free, upgrade anytime

FAQ

Do you support authenticated endpoints?

Yes. You can add custom headers including Authorization headers, API keys, and bearer tokens to authenticate your requests.

Can I monitor POST, PUT, and DELETE endpoints?

Yes. We support all HTTP methods including GET, POST, PUT, PATCH, and DELETE. You can also send custom request bodies.

How do you handle rate limits?

Our checks are designed to be lightweight. We send a single request per check interval (1-5 minutes). If your endpoint has strict rate limits, you can create a dedicated health check endpoint.

Can I validate response body content?

Currently we validate HTTP status codes and response times. Response body validation is on our roadmap.

Can I use the free plan for commercial APIs?

Yes. Commercial use is allowed on all plans, including Free. No restrictions.

Start monitoring your APIs