How to fix 431 Request Header Fields Too Large in React-Redux app

Question

I'm working through a MERN sign up/login auth tutorial on youtube that uses Redux. When attempting to POST a test user to the server in Postman, I receive the 431 header request is too large error response.

I've read in some places that clearing the cache/history in your browser works, so I've tried that to no avail. I've also added in a "Clear-Site-Data": "*" entry to the header request (in addition to "Content-Type": "application/json") which hasn't worked, either.

Client Side Code for Sign Up

  onSubmit = e => {
    e.preventDefault();
    const { name, email, password } = this.state;

    const newUser = {
      name,
      email,
      password
    };

    this.props.register(newUser);
  };

//redux actions
export const register = ({ name, email, password }) => dispatch => {

  const config = {
    headers: {
      "Content-Type": "application/json",
      "Clear-Site-Data": "*"
    }
  };

  // Request body
  const body = JSON.stringify({ name, email, password });

  axios
    .post('/api/users', body, config)
    .then(res =>
      dispatch({
        type: REGISTER_SUCCESS,
        payload: res.data
      })
    )
    .catch(err => {
      dispatch(
        returnErrors(err.response.data, err.response.status, 'REGISTER_FAIL')
      );
      dispatch({
        type: REGISTER_FAIL
      });
    });
};

The user sign up should be sending a name, email and password to my connected Mongo db, however, it halts me and redux hits the REGISTER_FAIL type I created returning the 431 error. Any help would be greatly appreciated. Thank you!

Answer 1

I had faced the same issue in my Angular Application. After spending a lot of time, I had found out that the issue is related with Node JS. We were using Node JS v12.x.x, and in this version, max-http-header-size reduced to 8KB from 80KB. And the auth token which I had was of around 10KB. That's why, when I reload the app, browser starts giving '431 request header fields too large' error for some of the files. I had updated the Node JS v14.x.x and it starts working again because in v14.0.0, max-http-header-size has been increased to 16KB.

Hope it will be helpful.

Answer 2

I had similar problems with just using localhost(not limited to redux). Maybe this might help.
Put this into url: chrome://settings/?search=cache
Click on Clear Browsing data.
Tick cookies and other site data (Important since cookies is in HTTP header) TIck cached images and files (might be optional)