Troubleshooting of HTTP errors - Revision history

Planetoid at 08:49, 11 June 2026

2026-06-11T08:49:52Z

← Older revision		Revision as of 16:49, 11 June 2026
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	__TOC__		__TOC__

	== ~~400 Bad Request~~ ==		== Troubleshooting HTTP Status Errors ==

	~~Root cause of~~ 400 Bad Request~~. HTTP Error 400. The request is badly formed.~~		=== 400 Bad Request ===
	* "the server cannot or will not process the request due to something that is perceived to be a client error (for example, malformed request syntax, invalid request message framing, or deceptive request routing)"

	~~Possible solution~~:		Root cause: The request itself is malformed. According to the spec, this means "the server cannot or will not process the request due to something perceived to be a client error" — such as invalid syntax, incorrect request message framing, or deceptive request routing.
	* Modify the request ~~headers~~

	== 403 Forbidden ~~Error~~ ==		Possible fix:
			* Review and correct the request headers

			=== 403 Forbidden ===

	See: [[How to fix the 403 forbidden error]]		See: [[How to fix the 403 forbidden error]]

	== 404 ~~File~~ Not Found ==		=== 404 Not Found ===
	~~Solution: Check if the accessed link is correct, see "404 Not Found \| Possible solutions for pages not found"~~

	~~== 405 Method Not Allowed Error ==~~		Fix: Verify that the URL is correct. For more details, see
	~~Solution~~: ~~Check if~~ the ~~accessed file or resource supports the HTTP protocol being used~~. For ~~example~~, ~~if the resource is restricted to POST requests but you're using GET~~.		[[404 Not Found]], possible solutions for pages not found".

	== ~~414 Request-URI Too Large~~ ==		=== 405 Method Not Allowed ===
	~~Solution: Change the request protocol to POST instead of GET~~

	== 415 Unsupported Media Type ==		Fix: Confirm that the target resource supports the HTTP method you're using. For example, the endpoint may only accept POST requests while you're sending a GET request.

			=== 414 Request-URI Too Large ===

			Fix: Switch from GET to POST so the data is sent in the request body instead of the URL.

			=== 415 Unsupported Media Type ===

			Fix: Explicitly declare the correct Content-Type or Content-Encoding in the request, or access the data directly. For instance, when calling a RESTful API, this error can often be resolved by adding the following header:

	Solution: "Set the Content-Type or Content-Encoding in the request or direct access to the data." For example: When encountering this error with RESTful API, a possible solution is to add to the HTTP Headers:
	<pre>		<pre>
	Content-Type: application/json		Content-Type: application/json
	</pre>		</pre>

	== 429 Too Many Requests ==		=== 429 Too Many Requests ===
	~~Root Cause:~~

	* ~~Accessing~~ website ~~resources~~ or ~~web service~~ API ~~too~~ frequently		Root cause:
			* The client is hitting the website or API more frequently than the service allows.

	~~Solutions~~:		Fixes:
			* '''Throttle your requests''': Add or increase a delay between requests based on your usage pattern and the service's limits (e.g., pause 1 second between calls).
			* '''Check the API rate limits''': Consult the provider's documentation for limits such as Requests Per Minute (RPM) or Requests Per Day (RPD), and find out whether you can request a higher quota.
			* '''Use exponential backoff''': Detect HTTP 429 responses in your
			application, then retry with progressively longer delays (e.g., 2s → 4s → 8s) until the request succeeds or a maximum retry count is reached.

	* '''Adjust the delay time''' based on your usage patterns and the service's limits e.g. Increase the delay time between requests (e.g., add a 1-second pause between each request).		=== 502 Bad Gateway ===
	* If accessing a web service API, Please refer to the documentation to understand the API access rate limits, such as: (1) "Requests Per Minute" (RPM) – the maximum number of API requests you can make per minute, or (2) "Requests Per Day" (RPD) – the maximum number of API requests you can make per day. Check if you can request a higher quota limit from the service provider
	* '''Implement exponential backoff retry mechanism''': Detect rate limit errors (HTTP 429) in your application. Increase the delay time with each failed retry (e.g., 2 seconds, 4 seconds, 8 seconds). Continue retrying until the request succeeds or maximum retry count is reached.

	~~== 502 Bad Gateway ==~~
	Cause:		Cause:
	* ~~Error occurs~~ between network devices~~, users cannot~~ directly ~~handle it~~.		* A failure between upstream network devices/servers — not something the end user can fix directly.

	~~Solutions~~:		Fixes:
	* ~~Bypass browser cache,~~ refresh the page		* Hard-refresh the page to bypass the browser cache
	* ~~Try reconnecting after~~ a ~~while~~		* Wait a moment and try again

	== Error 1020: Access Denied ==		=== Error 1020: Access Denied ===
	* See ~~link for understanding how to resolve~~ Error 1020 Access Denied to ~~get~~ your website ~~back online~~		* See the linked guide on resolving Error 1020 (Access Denied) to restore access to your website.

	~~<pre>~~
	~~Content-Type: application/json~~
	~~</pre>~~

	== HTTP Cats or Dogs ==		== HTTP Cats or Dogs ==

Planetoid: /* Error 1020: Access Denied */

2026-06-11T08:43:07Z

Error 1020: Access Denied

← Older revision		Revision as of 16:43, 11 June 2026
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	Content-Type: application/json		Content-Type: application/json
	</pre>		</pre>

			== HTTP Cats or Dogs ==

	<div style="zoom: 0.4;">		<div style="zoom: 0.4;">
	https://http.cat/200.jpg		https://http.cat/200.jpg
	</div>		</div>
	From HTTP Cats		From [https://http.cat/ HTTP Cats]

	Related websites:		Related websites:

Planetoid at 04:15, 11 June 2026

2026-06-11T04:15:48Z

← Older revision		Revision as of 12:15, 11 June 2026
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	</pre>		</pre>

			<div style="zoom: 0.4;">
	https://http.cat/200.jpg		https://http.cat/200.jpg
			</div>
	From HTTP Cats		From HTTP Cats

Planetoid: /* Mock HTTP status error pages tools */

2026-06-11T03:20:41Z

Mock HTTP status error pages tools

← Older revision		Revision as of 11:20, 11 June 2026
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	== Other possible root causes ==		== Other possible root causes ==
	* CDN (Content delivery network)		* CDN (Content delivery network)

	~~== Mock HTTP status error pages tools ==~~
	~~The website that returns 500 (and other) HTTP response codes for testing~~

	* [https://the-internet.herokuapp.com/status_codes The Internet]<ref>[https://stackoverflow.com/questions/24736134/is-there-a-website-that-returns-500-and-other-http-response-codes-for-testing httpresponse - Is there a website that returns 500 (and other) HTTP response codes for testing? - Stack Overflow]</ref>: e.g. [https://the-internet.herokuapp.com/status_codes/500 500]
	* [https://httpstatus.io/ Bulk URL HTTP Status Code, Header & Redirect Checker \| httpstatus.io] e.g. [https://mock.httpstatus.io/500 500]
	* [https://www.postman.com/postman/published-postman-templates/documentation/ae2ja6x/postman-echo Postman Echo] e.g. [https://postman-echo.com/status/500 500]


	== Mock HTTP status error page tools ==		== Mock HTTP status error page tools ==

Planetoid: /* Related pages */

2026-06-11T03:14:47Z

@@ Line 69: / Line 69: @@
 == Other possible root causes ==
 * CDN (Content delivery network)
 == Related pages ==
@@ Line 74: / Line 89: @@
 * [[Troubleshooting of curl errors]]
 * [[Test connectivity for the web service]]
 == References ==

Planetoid: /* Related pages */

2026-05-29T08:38:01Z

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	* [[Troubleshooting of curl errors]]		* [[Troubleshooting of curl errors]]
	* [[Test connectivity for the web service]]		* [[Test connectivity for the web service]]
			* [https://the-internet.herokuapp.com/status_codes The Internet]: The website that returns 500 (and other) HTTP response codes for testing<ref>[https://stackoverflow.com/questions/24736134/is-there-a-website-that-returns-500-and-other-http-response-codes-for-testing httpresponse - Is there a website that returns 500 (and other) HTTP response codes for testing? - Stack Overflow]</ref>

	== References ==		== References ==

Planetoid: /* 429 Too Many Requests */

2025-06-17T08:55:35Z

429 Too Many Requests

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	* '''Adjust the delay time''' based on your usage patterns and the service's limits e.g. Increase the delay time between requests (e.g., add a 1-second pause between each request).		* '''Adjust the delay time''' based on your usage patterns and the service's limits e.g. Increase the delay time between requests (e.g., add a 1-second pause between each request).
	* If accessing a web service API, ~~read~~ the documentation to understand the API's rate limits (~~RPM:~~ Requests Per Minute or ~~RPD:~~ Requests Per Day). Check if you can request a higher quota limit from the service provider		* If accessing a web service API, Please refer to the documentation to understand the API access rate limits, such as: (1) "Requests Per Minute" (RPM) – the maximum number of API requests you can make per minute, or (2) "Requests Per Day" (RPD) – the maximum number of API requests you can make per day. Check if you can request a higher quota limit from the service provider
	* '''Implement exponential backoff retry mechanism''': Detect rate limit errors (HTTP 429) in your application. Increase the delay time with each failed retry (e.g., 2 seconds, 4 seconds, 8 seconds). Continue retrying until the request succeeds or maximum retry count is reached.		* '''Implement exponential backoff retry mechanism''': Detect rate limit errors (HTTP 429) in your application. Increase the delay time with each failed retry (e.g., 2 seconds, 4 seconds, 8 seconds). Continue retrying until the request succeeds or maximum retry count is reached.

Planetoid: /* 429 Too Many Requests */

2025-06-17T08:52:15Z

429 Too Many Requests

← Older revision		Revision as of 16:52, 17 June 2025
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	* '''Adjust the delay time''' based on your usage patterns and the service's limits e.g. Increase the delay time between requests (e.g., add a 1-second pause between each request).		* '''Adjust the delay time''' based on your usage patterns and the service's limits e.g. Increase the delay time between requests (e.g., add a 1-second pause between each request).
	* If accessing a web service API, read the documentation to understand the API's rate limits. Check if you can request a higher quota limit from the service provider		* If accessing a web service API, read the documentation to understand the API's rate limits (RPM: Requests Per Minute or RPD: Requests Per Day). Check if you can request a higher quota limit from the service provider
	* '''Implement exponential backoff retry mechanism''': Detect rate limit errors (HTTP 429) in your application. Increase the delay time with each failed retry (e.g., 2 seconds, 4 seconds, 8 seconds). Continue retrying until the request succeeds or maximum retry count is reached.		* '''Implement exponential backoff retry mechanism''': Detect rate limit errors (HTTP 429) in your application. Increase the delay time with each failed retry (e.g., 2 seconds, 4 seconds, 8 seconds). Continue retrying until the request succeeds or maximum retry count is reached.

Planetoid: /* 429 Too Many Requests */

2025-04-29T03:52:33Z

429 Too Many Requests

← Older revision		Revision as of 11:52, 29 April 2025
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	== 429 Too Many Requests ==		== 429 Too Many Requests ==
	Cause:		Root Cause:
	* Accessing website resources too frequently
			* Accessing website resources or web service API too frequently

	Solutions:		Solutions:
	* Adjust ~~access frequency~~
	* If accessing a web service API, read the documentation to understand the API's rate limits		* '''Adjust the delay time''' based on your usage patterns and the service's limits e.g. Increase the delay time between requests (e.g., add a 1-second pause between each request).
			* If accessing a web service API, read the documentation to understand the API's rate limits. Check if you can request a higher quota limit from the service provider
			* '''Implement exponential backoff retry mechanism''': Detect rate limit errors (HTTP 429) in your application. Increase the delay time with each failed retry (e.g., 2 seconds, 4 seconds, 8 seconds). Continue retrying until the request succeeds or maximum retry count is reached.

	== 502 Bad Gateway ==		== 502 Bad Gateway ==

Planetoid at 16:14, 28 April 2025

2025-04-28T16:14:38Z

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	HTTP status code		HTTP status code

			{{LanguageSwitcher \| content = [[Troubleshooting of HTTP errors \| EN]], [[Troubleshooting of HTTP errors in Mandarin \| 漢字]] }}

	__TOC__		__TOC__
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	Root cause of 400 Bad Request. HTTP Error 400. The request is badly formed.		Root cause of 400 Bad Request. HTTP Error 400. The request is badly formed.
	* "the server cannot or will not process the request due to something that is perceived to be a client error (for example, malformed request syntax, invalid request message framing, or deceptive request routing)"~~<ref>[https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/400 400 Bad Request - HTTP \| MDN]</ref>~~		* "the server cannot or will not process the request due to something that is perceived to be a client error (for example, malformed request syntax, invalid request message framing, or deceptive request routing)"

	~~Possibile~~ solution:		Possible solution:
	* Modify the request headers		* Modify the request headers

	== 403 Forbidden Error ==		== 403 Forbidden Error ==

	[[How to fix the 403 forbidden error]]		See: [[How to fix the 403 forbidden error]]

	== 404 File Not Found ==		== 404 File Not Found ==
	~~解決方法：檢查存取的連結是否正確，詳見 [[~~404 Not Found \| ~~找不到網頁的可能解決方法]]~~		Solution: Check if the accessed link is correct, see "404 Not Found \| Possible solutions for pages not found"

	== 405 Method Not Allowed Error ==		== 405 Method Not Allowed Error ==
	~~解決方法：檢查存取的文件或資源支援呼叫使用的~~ HTTP protocol ~~<ref>[https://dotblogs.com~~.~~tw/cotton/2018/03/01/132336 使用Http Post呼叫api卻收到405 method not allowed \| 攻城獅的學習筆記 - 點部落]</ref>，例如限制使用~~ POST ~~，卻使用~~ GET ~~存取。~~		Solution: Check if the accessed file or resource supports the HTTP protocol being used. For example, if the resource is restricted to POST requests but you're using GET.

	== 414 Request-URI Too Large ==		== 414 Request-URI Too Large ==
	~~解決方法：請求協議改用~~ POST ~~而不是~~ GET~~<ref>[https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/414 414 URI Too Long - HTTP \| MDN]</ref>~~		Solution: Change the request protocol to POST instead of GET

	== 415 Unsupported Media Type ==		== 415 Unsupported Media Type ==

	~~解決方法：「於請求中設置的 {{kbd \| key=~~Content-Type~~}} 或 {{kbd \| key=~~Content-Encoding~~}} 或對資料的直接訪問」。參考資料：[https~~:~~//developer.mozilla.org/zh-TW/docs/Web/HTTP/Status/415 415 Unsupported Media Type - HTTP \| MDN]~~		Solution: "Set the Content-Type or Content-Encoding in the request or direct access to the data." For example: When encountering this error with RESTful API, a possible solution is to add to the HTTP Headers:

	~~例如：RESTful~~ API ~~遇到該錯誤，可能解決方式是~~ HTTP Headers 加入
	<pre>		<pre>
	Content-Type: application/json		Content-Type: application/json
Line 36:		Line 36:

	== 429 Too Many Requests ==		== 429 Too Many Requests ==
	~~原因：~~		Cause:
	* ~~太頻繁存取網站資源~~		* Accessing website resources too frequently

	~~解決方法：~~
	* 調整存取頻率
	* 如果是存取網路服務 API，請閱讀文件了解 API 本身的存取頻率限制 (Rate Limits)

	~~參考資料~~		Solutions:
	* ~~[https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/429 429 Too Many Requests - HTTP \| MDN]~~		* Adjust access frequency
			* If accessing a web service API, read the documentation to understand the API's rate limits

	== 502 Bad Gateway ==		== 502 Bad Gateway ==
	~~原因：~~		Cause:
	* 因為是網路設備間發生錯誤，使用者並無法直接處理<ref>[https:~~//hostingpill.com/zh-TW/502%E9%8C%AF%E8%AA%A4%E7%9A%84%E7%B6%B2%E9%97%9C/ 什麼是502 Bad Gateway錯誤以及如何解決（輕鬆修復指南）]</ref>。~~		* Error occurs between network devices, users cannot directly handle it.

	~~解決方法：~~
	* ~~[https://zh~~.~~wikipedia.org/zh-tw/Help:%E7%BB%95%E8%BF%87%E6%B5%8F%E8%A7%88%E5%99%A8%E7%BC%93%E5%AD%98 繞過瀏覽器快取]，瀏覽器重新整理頁面~~
	* 過一陣子再重新連線

	~~參考資料~~		Solutions:
	* ~~[https://developer.mozilla.org/zh-TW/docs/Web/HTTP/Status/502 502 Bad Gateway - HTTP \| MDN]~~		* Bypass browser cache, refresh the page
			* Try reconnecting after a while

	== Error 1020: Access Denied ==		== Error 1020: Access Denied ==
	* ~~[https://www.affde.com/zh-TW/error-~~1020~~-access-denied.html 了解如何解決錯誤 1020 訪問被拒絕以使您的網站重新上線 - Affde營銷]~~		* See link for understanding how to resolve Error 1020 Access Denied to get your website back online

	<pre>		<pre>
Line 64:		Line 58:
	</pre>		</pre>

	: https://http.cat/200.jpg		https://http.cat/200.jpg
	: From ~~[https://http.cat/~~ HTTP Cats]		From HTTP Cats

	Related websites		Related websites:
	* [https://httpstatusdogs.com/ HTTP Status Dogs]		* [https://httpstatusdogs.com/ HTTP Status Dogs]

	== Other ~~possibile~~ root ~~cause~~ ==		== Other possible root causes ==
	* CDN (~~[https://en.wikipedia.org/wiki/Content_delivery_network~~ Content delivery network])		* CDN (Content delivery network)

	== Related pages ==		== Related pages ==