Test your integration with GOV.UK One Login
Once you’ve integrated your service with Authorization Code Flow, you can test your integration with GOV.UK One Login.
You have 2 options for testing:
- the GOV.UK One Login simulator, which lets you test and verify specific user information and error codes
- the GOV.UK One Login integration environment, which lets you test end to end user journeys
Compare GOV.UK One Login simulator and integration environments
The GOV.UK One Login simulator does not currently support all GOV.UK One Login features. Use this table to understand the difference between the GOV.UK One Login simulator and the integration environment.
| Feature | GOV.UK One Login simulator | GOV.UK One Login Integration environment |
|---|---|---|
| Can test error messages | Yes | No |
| Can test the landing page URL | No | No |
| Can test the mobile journey | No | No |
| Can test the web journey | Yes | Yes |
| Configurable response data | Yes | No. You need to request fictional users and their knowledge-based verification (KBV) answers to help you test your journeys. Email GOV.UK One Login to access this test user data. |
| Configure with the GOV.UK One Login admin tool | No. There’s further guidance about configuring the GOV.UK One Login simulator for more information. | Yes |
| Runs locally | Yes | No |
| Runs on a publicly accessible endpoint | No, unless you host it online. | Yes |
Supports client_secret_post
|
No | Yes |
| Supports performance testing | Yes, in interactive_mode only. |
No |
Supports permit missing nonce
|
No | Yes |
| Uses the GOV.UK One Login API | Yes | Yes |
This page was last reviewed on 7 September 2026.