Why cannot the request succeed when the configuration is correct? The error is 400?

[maochengliang]

[binghun9806]

I also encountered this problem, I think the problem is on the POST/content of Operation, but I can't find how to modify it.

[georgebashi]

I had the same thing when I was using the browserless/chrome container from a previous deploy. I switched it to ghcr.io/browserless/chromium and everything started working 🎉

[ivanovd]

@georgebashi what about if we use the cloud browserless service? Would that matter? I am getting 400 when I use the browserless cloud with my cloud API key, not the self-hosted browserless.

[rcimedia]

I am getting same error when using any Launch sub-option ...

browserless.io:server:error HTTP query-params contain errors sending 400:"launch[stealth]" is not allowed +1m

[KIC]

In the docker logs of n8n there is the issue:

browserless    | 2025-08-16T10:41:01.097Z browserless:system Malformed incoming request: ValidationError: "waitForTimeout" is not allowed

the parameter can not be removed from the config, and making it null is not enough.

Also note that setting a suer agent is now obligatory.

[MCTRACO]

Yes @KIC, this should be fixed and as of right now the nodes do not work at all. I am making a fork in a attempt to fix this.

[dsegovia90]

Same issue here, can't use this at all due to this error

[JoeKL]

Also encountered the same error while trying to implement a small crawling function in a workflow. Would be really nice to see that fixed!

[CyberSardinha]

Yes @KIC, this should be fixed and as of right now the nodes do not work at all. I am making a fork in a attempt to fix this.

I´ve saw your fork. is there anyway to install it directly? Iḿ having the same problem and I can't seem to find how to install your fork.:/

[alexandre-vl]

I fixed it by adding an object for the userAgent and increased the timeout because by default its 2 milliseconds :

[ostrolucky]

I've created bunch of fixes for this in #20. I don't know if issue was that browserless API changed since this node has been created or version 2 of this node never got properly finished in way to make it work stable with browserless, but this node sends wrong data to browserless in some instances. Instances I have personally ran into is userAgent and cookies, hence that's what I fixed.

If you would like to use these fixes already, without waiting for merge and tag, you can extract this zip file by replacing /home/node/.n8n/nodes/node_modules/n8n-nodes-browserless/dist (assuming you use docker - this is an internal path inside docker container)

[MatveyMirman]

Works using browserless version v2.14.0

[adraeger]

Hi @minhlucvan,
any chance this PR will be merged? We're running into the exact same userAgent validation error with Browserless v2.42 and had to fall back to raw HTTP requests as a workaround. The fix looks clean and straightforward — would be great to get it released.