> For the complete documentation index, see [llms.txt](https://docs.snyk.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.snyk.io/scan-fix-and-prevent/scan-with-snyk/snyk-api-web/review-and-fix/http-status-codes-in-target-scans.md). # HTTP status codes in target scans When analyzing your [target scan results](/scan-fix-and-prevent/scan-with-snyk/snyk-api-web/review-and-fix/interpret-target-scan-results.md), you can find details about the crawler and the scanner, including a list of HTTP response status codes. This information provides an overall view of how the application responds to the crawler and scanner activities. When looking at them, keep the following in mind: * **HTTP 2XX** - These are success status codes, that is, successful requests from Snyk API & Web. * **HTTP 3XX** - These redirection status codes indicate normal behavior of the application. They most likely result from the wide range of request combinations when Snyk crawls the application and searches for vulnerabilities. * **HTTP 4XX** - These client error status codes indicate normal behavior of the application. They most likely result from the wide range of request combinations when Snyk crawls the application and searches for vulnerabilities. * **HTTP 5XX** - These server error status codes indicate that the application is not responding well to Snyk requests because of server problems. Check the server to understand why this is happening. ## Troubleshooting Although some reported HTTP status codes indicate normal behavior (because the applications or APIs are doing what they are supposed to), some cases need troubleshooting and fixing. ### HTTP 5XX status codes The server is not responding well. Look into the server to find any misbehaviors or problems and fix them. ### HTTP 401 status code with API targets Snyk cannot log in to scan the API. In the Snyk app, navigate to your target settings and review the authentication according to how the API was specified: * **Swagger/OpenAPI** - The authentication configuration is in the target settings. Review and fix it. * **Postman Collection** - The authentication is implemented in the Postman Collection. Review the implementation, fix it, export the collection, and upload it in the target settings or submit the Postman Collection schema URL. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://docs.snyk.io/scan-fix-and-prevent/scan-with-snyk/snyk-api-web/review-and-fix/http-status-codes-in-target-scans.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.