Why is ngrok returning HTML?

Using ngrok for creating a proxy of your local backend is in every development journey, mostly when you want to expose a local service using an environment variable.

I found a problem that entertained me the whole afternoon while trying to deploy a Gmail Addon using Google App Script.
I couldn't make a request since the response returns HTML.
ngrok tries to ensure that if someone shares this URL with another part, this part knows that this URL is a tunnel to another endpoint.

The solution is straightforward. We should set ngrok-skip-browser-warning in the headers of the response with any value, e.g

// Only for local development
headers['ngrok-skip-browser-warning'] = 'skip-browser-warning';

Comments

[mayur kalwar]

Thanks Brother . Wasted my whole 2 hours , struggling every second . I searched chatgpt,deepseek no one was able to provide this.

Thanks a lot again

[TTUmejiaku]

thank you so much for this.

[Joseph Akinwole]

Thank you for this. I'm having this issue too

Pls what headers are you talking about