ngrok pioneered localhost tunneling. stunl takes it further with multi-port tunnels, full protocol support, and transparent pricing.
| Feature | stunl | ngrok |
|---|---|---|
| Starting Price | Free / $10/mo | Free / $8-20/mo |
| Multi-port Tunnels | Yes | No (need multiple endpoints) |
| HTTP/HTTPS | Yes | Yes |
| TCP Tunnels | Yes (Pro+) | Yes (CC required on free) |
| UDP Tunnels | Yes (Pro+) | No |
| WebSocket | Yes | Yes |
| Free Bandwidth | 2 GB/mo | 1 GB/mo |
| Concurrent Tunnels | 1 (Free) / 5 (Pro) each tunnel carries unlimited ports ↓ | 3 (all tiers) 1 port per endpoint |
| Bandwidth (paid) | 50 GB/mo (Pro) | 5 GB (then $0.10/GB) |
| Session Limits | 1 hr (Free) / None (Pro) | None (with account) |
| Interstitial Page | No (Pro) | Yes (free tier) |
| Custom Subdomain | Yes (Pro) | Paid only |
Expose your frontend (port 3000), API (port 8080), and database (port 5432) through one URL. With ngrok, you'd need 3 separate endpoints with 3 different URLs.
$ stunl -ports 'web:3000,api:8080,db:5432'
ngrok doesn't support UDP at all. stunl handles UDP natively for game servers, VoIP, DNS, and IoT applications.
$ stunl -port 27015 -protocol udp
stunl Pro includes 50GB/month. ngrok's Hobbyist plan ($8-10/mo) includes only 5GB, then charges $0.10/GB overage. At similar usage, ngrok costs more.
Generous free tier (2GB bandwidth, WebSocket, multiport). Pro at $10/month includes 50GB with no per-endpoint fees or surprise overage charges. ngrok's metered billing can add up fast.
Both have HTTP inspection. stunl goes further.
| Developer Tool | stunl | ngrok |
|---|---|---|
| Request inspection | Yes | Yes |
| Request replay | Yes | Yes |
| Edit request before replay | Yes | No |
| Request diff/compare view | Yes | No |
| Webhook signature verification | 7 providers | Limited |
| Export to cURL/HAR | 4 formats | Yes |
| Shareable request snapshots | Yes | No |
| Response mocking | Yes | No |
| Chaos/latency injection | Yes | No |
| Request breakpoints | Yes | No |
| File sharing | Yes | No |
| Terminal sharing | Yes | No |
Modify the HTTP method, headers, or body before replaying a request. Test edge cases without changing your code. ngrok only replays the exact original request.
Compare two requests side-by-side. See exactly what changed between webhook deliveries. Perfect for debugging Stripe retry logic or GitHub event differences.
Verify webhook signatures from Stripe, GitHub, Slack, Twilio, Shopify, Linear, and Discord. Enter your signing secret, see if the signature is valid.
Share your terminal for pair programming. Multiple viewers, read-only or interactive mode. Access via SSH or browser. ngrok doesn't offer this.
Return fake responses or inject latency/errors. Test error handling without touching your server code.
Pause HTTP requests mid-flight, inspect them, modify headers/body, then forward or drop. Like a debugger for your API.
Frontend + API + Database on one URL
UDP-based multiplayer games
Stripe, GitHub, Twilio callbacks
Remote access to sensors, cameras
No credit card required for either
What you get at different price points
Start free. No credit card required.
Free tier available. No credit card required.