ngrok

ngrok puts your localhost on the internet. That's the one-line explanation, and it's the reason millions of developers use it. You're running a web server on your laptop at localhost:3000 and you need to show it to a client, test a webhook from Stripe, or let a teammate hit your API. Normally you'd have to deploy to a staging server, configure DNS, set up SSL, and wait. With ngrok, you run `ngrok http 3000` and get a public HTTPS URL that tunnels traffic directly to your local machine. The whole process takes about five seconds. ngrok works by establishing an outbound TLS connection from your machine to ngrok's edge servers. When someone visits your ngrok URL, the request travels through ngrok's infrastructure and arrives at your local server as if it came from localhost. The response goes back the same way. From the outside, it looks like a normal website. From your side, it looks like local traffic. No firewall rules to change, no port forwarding to configure, no router settings to touch. Founded by Alan Shreve and backed by $75M in Series A funding (2024), ngrok has grown from a simple tunneling tool into a full ingress platform. The free tier still does what most developers need—HTTP tunnels with a random subdomain. The paid tiers add custom domains, IP restrictions, OAuth authentication at the tunnel level, TCP tunnels for non-HTTP protocols, and a web inspection dashboard that lets you replay and modify requests. In 2026, ngrok processes billions of connections per month and is the default tool developers reach for when they need to expose local services to the internet. The platform now supports AI Gateway capabilities and Kubernetes ingress in addition to its core tunneling features. The competition has grown—Cloudflare Tunnel, Tailscale Funnel, and localhost.run offer alternatives—but ngrok remains the most widely used because of its simplicity, its inspection UI, and its decade of reliability. When you search 'webhook testing' or 'expose localhost', ngrok is the answer.