HTTP 429 / 454 / 455 Blocked

• HTTP 429
• HTTP 454
• HTTP 455
• About security checks
• Services whitelisted
  • Bots pretending to be approved services
  • Requirements for whitelist additions

Simply.com uses an advanced protection system (Web Application Firewall) to prevent and block attacks, misuse and exploitation of vulnerabilities in our customers' websites.

¶HTTP 429

The error code is "temporary" and tells the visitor that they should/can try again later.

You may see this error code for various reasons, e.g.:

• The website is currently receiving an unusually high number of requests or is actively under attack.
• A known crawler that has made too many requests within a short period. Most crawlers recognise this error code and will automatically try again at a later time.
• The error code can also come from the website's own code and protection (outside our control).
• The visit comes from an IP address that makes an enormous number of requests.

When you encounter this error code, the web server may perform an automatic security check of your browser before letting you continue. The check is there to protect the website against bots and automated attacks that can overload the server or attempt to exploit vulnerabilities.

¶HTTP 454

This response code can occur if:

• You are using a very old browser that lacks the features a modern web is built on.
• You are pretending to be a very old browser that lacks the features a modern web is built on.
• The visit comes from an IP address with a poor "reputation" that is globally known for attacks.

All normal browsers can complete this check without problems and will subsequently receive an HTTP 200 response code.

If you are the owner of the website and find that legitimate visitors, integrations or devices are affected, first contact the owner of this integration and ask them to investigate the problem. Check which user-agent is being sent.

¶HTTP 455

This response code can occur if an individual request is blocked due to a firewall rule.

You can see the precise reason for the block by reviewing the logs for your product. This is done under "Webserver logs" in our Control Panel.
Based on the reason, you can most likely resolve the block.

¶About security checks

All normal browsers can complete this check without problems and will subsequently receive an HTTP 200 response code.
In most cases, the check takes place in the background, and an ordinary browser with JavaScript and cookies enabled gets through in a few seconds without you even noticing. Once the check has been passed, you can freely navigate the website for a while before it is possibly renewed.

If you get stuck in the check, you can try reloading the page, updating your browser or visiting the page from another device or network connection.

¶Services whitelisted

Known third-party services such as Googlebot, OpenAI, Anthropic, Bing, LinkedIn, Jetpack, PayPal, Facebook, ManageWP etc. are whitelisted in our security filter.

We do not whitelist security services, as our security filter is precisely a security element – and removing it in order to scan for security issues therefore does not make much sense.

¶Bots pretending to be approved services

If you are investigating blocks, note that many bots pretend to be these known services in an attempt to get through the security filter. Therefore, always check whether it is actually an approved service that has been blocked (based on IP address).

¶Requirements for whitelist additions

In general, our WAF behaves properly towards proper requests, i.e. requests that comply with common rules. If you wish to whitelist a known third-party service, we can offer this if there is a public and maintained URL with a list of the IP addresses in use.
Please investigate whether a block is actually occurring before requesting whitelisting.