# Title: Antigravity IDE Google OAuth Login Fails with HTTP ERROR 431

**URL:** <https://discuss.ai.google.dev/t/title-antigravity-ide-google-oauth-login-fails-with-http-error-431/181849>\
**Category:** Google Antigravity\
**Tags:** bug\
**Created:** [September 8, 2026, 6:24am UTC](https://discuss.ai.google.dev/t/title-antigravity-ide-google-oauth-login-fails-with-http-error-431/181849 "2026-09-08T06:24:39Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Washim\_Reja](https://d1dlmcr85iqnpo.cloudfront.net/user_avatar/discuss.ai.google.dev/washim_reja/32/148158_2.png) [@Washim\_Reja](https://discuss.ai.google.dev/u/Washim_Reja)\
**Post date:** [September 8, 2026, 6:24am UTC](https://discuss.ai.google.dev/t/title-antigravity-ide-google-oauth-login-fails-with-http-error-431/181849/1 "2026-09-08T06:24:39Z")

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Hello Google Antigravity Team,

I am unable to complete the Google sign-in process in Antigravity IDE.

After clicking “Continue with Google”, the Google authentication completes successfully. However, when the browser redirects back to the local OAuth callback server, the following error occurs:

HTTP ERROR 431 – This page isn’t working

Callback URL: http:/localhost:56180/oauth-callback

Environment:

OS: Windows 11

Application: Google Antigravity IDE

Browser: Google Chrome

Google Account: Personal Gmail account

The Google authentication itself works correctly, but the localhost OAuth callback fails with HTTP 431, preventing Antigravity IDE from completing the login process.

I have attached screenshots showing:

Antigravity IDE login screen

Google authentication confirmation

HTTP ERROR 431 on localhost OAuth callback

Please investigate this OAuth callback issue.

Thank you.

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<div class="post-metadata">

**Author:** ![Ambati\_Rajendra](https://d1dlmcr85iqnpo.cloudfront.net/user_avatar/discuss.ai.google.dev/ambati_rajendra/32/31584_2.png) [@Ambati\_Rajendra](https://discuss.ai.google.dev/u/Ambati_Rajendra)\
**Post date:** [September 8, 2026, 11:59am UTC](https://discuss.ai.google.dev/t/title-antigravity-ide-google-oauth-login-fails-with-http-error-431/181849/2 "2026-09-08T11:59:12Z")

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**Hi @[Washim\_Reja](https://discuss.ai.google.dev/u/washim_reja),**

Could you please follow these steps:

- 
  1. **Clear `localhost` Cookies in Google Chrome (Direct Fix)**:

  2. **Authenticate in Chrome Incognito Window** :

  3. **Use CLI Manual Authentication (Bypasses Local Callback Server)**:

Let me know after you tried is the issue resolves or not?