Our API is based on HTTP requests and supports both HTTP and HTTPS protocols.

API endpoints:

• https://api.bigcaptcha.com/in.php is used to submit a captcha
• https://api.bigcaptcha.com/res.php is used to get the captcha solution

The process of solving captchas with BigCaptcha is really easy and it’s mostly the same for all types of captchas:

1. Get your API key from your account settings page. Each user is given a unique authentication token, we call it API key. It’s a 32-characters string that looks like:
   1abc234de56fab7c89012d34e56fa7b8
   This key will be used for all your requests to our server.
2. Submit a HTTP POST request to our API URL: https://api.bigcaptcha.com/in.php with parameters corresponding to the type of your captcha.
   Server will return captcha ID or an error code if something went wrong.
3. Make a timeout: 20 seconds for reCAPTCHA, 5 seconds for other types of captchas.
4. Submit a HTTP GET request to our API URL: https://api.bigcaptcha.com/res.php to get the result.
   If captcha is already solved server will return the answer in format corresponding to the type of your captcha.
   By default answers are returned as plain text like: OK|Your answer. But answer can also be returned as JSON {“status”:1,”request”:”TEXT”} if json parameter is used.
   If captcha is not solved yet server will return CAPCHA_NOT_READY result. Repeat your request in 5 seconds.
   If something went wrong server will return an error code.

Normal Captcha is an image that contains distored but human-readable text. To solve the captcha user have to type the text from the image.

To solve the captcha with our service you have to submit the image with HTTP POST request to our API URL: https://api.bigcaptcha.com/in.php
Server accepts images in multipart or base64 format.

To solve the captcha with our service you have to submit the image with HTTP POST request to our API URL: https://api.bigcaptcha.com/in.php
Server accepts images in multipart or base64 format.

Multipart sample form

YOUR_APIKEY is Your API key.

Base64 sample form

YOUR_APIKEY is Your API key.

You can provide additional parameters with your request to define what kind of captcha you’re sending and to help workers to solve your captcha correctly. You can find the full list of parameters in the table below.

If everything is fine server will return the ID of your captcha as plain text, like: OK|2122988149 or as JSON {“status”:1,”request”:”2122988149″} if json parameter was used.

If something went wrong server will return an error. See Error Handling chapter for the list of errors.

Make a 5 seconds timeout and submit a HTTP GET request to our API URL: https://api.bigcaptcha.com/res.php providing the captcha ID. The list of parameters is in the table below.

If everything is fine and your captcha is solved server will return the answer as plain text, like: OK|TEXT or as JSON {“status”:1,”request”:”TEXT”} if json parameter was used.

Otherwise server will return CAPCHA_NOT_READY that means that your captcha is not solved yet. Just repeat your request in 5 seconds.

If something went wrong server will return an error. See Error Handling chapter for the list of errors.

List of POST request parameters for https://api.bigcaptcha.com/in.php

List of GET request parameters for https://api.bigcaptcha.com/res.php

Request URL example:

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https:/api.bigcaptcha.com/res.php?key=1abc234de56fab7c89012d34e56fa7b8&action=get&id=2122988149

reCAPTCHA V2 also known as I’m not a robot reCAPTCHA is a very popular type of captcha that looks like this:

Solving reCAPTCHA V2 with our new method is pretty simple:

1. Look at the element’s code at the page where you found reCAPTCHA.
2. 
3. Find a link that begins with www.google.com/recaptcha/api2/anchor or find data-sitekey parameter.
4. Copy the value of k parameter of the link (or value of data-sitekey parameter).
5. 
6. Submit a HTTP GET or POST request to our API URL: https://api.bigcaptcha.com/in.php with method set to userrecaptcha and provide the value found on previous step as value for googlekey and full page URL as value for pageurl. Sending proxies is not obligatory ar the moment but it’s recommended.
   You can find the full list of parameters in the table below.

Request URL example:

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https://api.bigcaptcha.com/in.php?key=1abc234de56fab7c89012d34e56fa7b8&method=userrecaptcha&googlekey=6Le-wvkSVVABCPBMRTvw0Q4Muexq1bi0DJwx_mJ-&pageurl=http://mysite.com/page/with/recaptcha

• If everything is fine server will return the ID of your captcha as plain text, like: OK|2122988149 or as JSON {“status”:1,”request”:”2122988149″} if json parameter was used.
  Otherwise server will return an error code.
• Make a 15-20 seconds timeout then submit a HTTP GET request to our API URL: https://api.bigcaptcha.com/res.php to get the result.
  The full list of parameters is in the table below.If captcha is already solved server will respond in plain text or JSON and return the answer token that looks like:

  03AHJ_Vuve5Asa4koK3KSMyUkCq0vUFCR5Im4CwB7PzO3dCxIo11i53epEraq-uBO5mVm2XRikL8iKOWr0aG50sCuej9bXx5qcviUGSm4iK4NC_Q88flavWhaTXSh0VxoihBwBjXxwXuJZ-WGN5Sy4dtUl2wbpMqAj8Zwup1vyCaQJWFvRjYGWJ_TQBKTXNB5CCOgncqLetmJ6B6Cos7qoQyaB8ZzBOTGf5KSP6e-K9niYs772f53Oof6aJeSUDNjiKG9gN3FTrdwKwdnAwEYX-F37sI_vLB1Zs8NQo0PObHYy0b0sf7WSLkzzcIgW9GR0FwcCCm1P8lB-50GQHPEBJUHNnhJyDzwRoRAkVzrf7UkV8wKCdTwrrWqiYDgbrzURfHc2ESsp020MicJTasSiXmNRgryt-gf50q5BMkiRH7osm4DoUgsjc_XyQiEmQmxl5sqZP7aKsaE-EM00x59XsPzD3m3YI6SRCFRUevSyumBd7KmXE8VuzIO9lgnnbka4-eZynZa6vbB9cO3QjLH0xSG3-egcplD1uLGh79wC34RF49Ui3eHwua4S9XHpH6YBe7gXzz6_mv-o-fxrOuphwfrtwvvi2FGfpTexWvxhqWICMFTTjFBCEGEgj7_IFWEKirXW2RTZCVF0Gid7EtIsoEeZkPbrcUISGmgtiJkJ_KojuKwImF0G0CsTlxYTOU2sPsd5o1JDt65wGniQR2IZufnPbbK76Yh_KI2DY4cUxMfcb2fAXcFMc9dcpHg6f9wBXhUtFYTu6pi5LhhGuhpkiGcv6vWYNxMrpWJW_pV7q8mPilwkAP-zw5MJxkgijl2wDMpM-UUQ_k37FVtf-ndbQAIPG7S469doZMmb5IZYgvcB4ojqCW3Vz6Q
  

  If captcha is not solved yet server will return CAPCHA_NOT_READY result. Repeat your request in 5 seconds.

  If something went wrong server will return an error code.

• Locate the element with id g-recaptcha-response and make it visible deleting display:none parameter.
  

  Please note: sometimes content on the page is generated dynamically and you will not see this element in html source.
  In such cases you have to explore javascript code that generates the content. “Inspect” option in Google Chrome can help in that.

  As an alternative you can just use javascript to set the value of g-recaptcha-response field:

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  document.getElementById("g-recaptcha-response").innerHTML="TOKEN";
   An input field will appear on the page. And you just have to paste the answer token to that field and submit the form.

• 
• Congratulations, you’ve passed the recaptcha
• 

List of GET/POST request parameters for https://api.bigcaptcha.com/in.php

List of GET request parameters for https://api.bigcaptcha.com/res.php

reCAPTCHA V3 is the newest type of captcha from Google. It has no challenge so there is no need for user interaction. Instead it uses a “humanity” rating – score.

reCAPTCHA V3 technically is quite similar to reCAPTCHA V2: customer receives a token from reCAPTCHA API which is then sent inside a POST request to the target website and verified via reCAPTCHA API.

The difference is now reCAPTCHA API returns rating of a user detecting whether he was a real human or a bot. This rating is called score and could be a number from 0.1 to 0.9. This score is passed to the website which then decides what to do with the user request.

Also there is a new parameter action allowing to process user actions on the website differently. After the verification of token reCAPTCHA API returns the name of the action user performed.

Our approach for solving reCAPTCHA V3
We’ve performed many experiments and figured out that if a user got score 0.1 on some website then he is likely to get the same score on other websites.

We are detecting the scores of our workers. Then when we’ve got a request for solving reCAPTCHA V3 with the minimal rating min_score we pass the captcha to the worker with the requested rating or higher. Most of the requests will get the requested rating on targer websites with reCAPTCHA V3.

How to solve reCAPTCHA V3 using 2Captcha:

1. First you’ve got to be sure the target website is actually using reCAPTCHA V3There should be V3 if:
   • there is no captcha and no images to click on
   • api.js script is loading with the render=sitekey parameter, for example:
     https://www.google.com/recaptcha/api.js?render=6LfZil0UAAAAAAdm1Dpzsw9q0F11-bmervx9g5fE
   • clients array of ___grecaptcha_cfg object is using index 100000: ___grecaptcha_cfg.clients[100000]
2. To start solving reCAPTCHA V3 using our API first you’ve got to find three parameters:sitekey – this parameter could be obtained from the URI of api.js as a value of render parameter. It could also be found inside URI of iframe with reCAPTCHA, in javascript code of the website where it’s calling grecaptcha.execute function or in ___grecaptcha_cfg configuration object.action – you’ve got to find this inspecting javascript code of the website looking for call of grecaptcha.execute function. Example: grecaptcha.execute(‘6LfZil0UAAAAAAdm1Dpzsw9q0F11-bmervx9g5fE’, {action: do_something}).
   Sometimes it’s really hard to find it and you’ve got to dig through all js-files loaded by website. You may also try to find the value of action parameter inside ___grecaptcha_cfg configuration object but usually it’s undefined. In that case you have to call grecaptcha.execute and inspect javascript code. If you can’t find it try to use the default value “verify” – our API will use it if you don’t provide action in your request.pageurl – full URL of the page where you see the reCAPTCHA V3.Now you need to understand the score you need to solve V3. You can’t predict what score is acceptable for the website you want to solve at. It can only be figured out by trial and error. The lowest score is 0.1 which means “robot”, the highest is 0.9 which means “human”. But most sites uses thresholds from 0.2 to 0.5 because real humans receive a low score oftenly. Our service is able to provide solutions which requires the score of 0.3. Higher score is extreamly rare among workers.
3. Having all necessary parameters stated above you may send request to our API.
4. Submit a HTTP GET or POST request to our API URL:
   https://api.bigcaptcha.com/in.php
   with method set to userrecaptcha and version set to v3 along with min_score set to score website requires, sitekey inside googlekey parameter and full page URL as value for pageurl. You have to include action parameter to or else we will use default value verify.List of request parameters below.URL request sample:

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   https://api.captcha.com/in.php?key=1abc234de56fab7c89012d34e56fa7b8&method=userrecaptcha&version=v3&action=verify&min_score=0.3
   &googlekey=6LfZil0UAAAAAAdm1Dpzsw9q0F11-bmervx9g5fE&pageurl=http://mysite.com/page/
   

5. If everything is fine server will return the ID of your captcha as plain text, like: OK|2122988149 or as JSON {“status”:1,”request”:”2122988149″} if json parameter was used.If something went wrong server will return an error. See Error Handling chapter for the list of errors.
6. Make a 10-15 seconds timeout and submit a HTTP GET request to our API https://api.bigcaptcha.com/res.php providing the captcha ID. The list of parameters is in the table below.If everything is fine and your captcha is solved server will return the answer as plain text or as JSON. The answer is a token like this:

   Copy to Clipboard
   03AHJ_Vuve5Asa4koK3KSMyUkCq0vUFCR5Im4CwB7PzO3dCxIo11i53epEraq-uBO5mVm2XRikL8iKOWr0aG50sCuej9bXx5qcviUGSm4iK4NC_Q88flavWhaTXSh0VxoihBwBjXxwXuJZ-WGN5Sy4dtUl2wbpMqAj8Zwup1vyCaQJWFvRjYGWJ_TQBKTXNB5CCOgncqLetmJ6B6Cos7qoQyaB8ZzBOTGf5KSP6e-K9niYs772f53Oof6aJeSUDNjiKG9gN3FTrdwKwdnAwEYX-F37sI_vLB1Zs8NQo0PObHYy0b0sf7WSLkzzcIgW9GR0FwcCCm1P8lB--gf50q5BMkiRH7osm4DoUgsjc_XyQiEmQmxl5sqZP7aKsaE-EM00x59XsPzD3m3YI6SRCFRUevSyumBd7KmXE8VuzIO9lgnnbka4-eZynZa6vbB9cO3QjLH0xSG3--o-fxrOuphwfrtwvvi2FGfpTexWvxhqWICMFTTjFBCEGEgj7_IFWEKirXW2RTZCVF0Gid7EtIsoEeZkPbrcUISGmgtiJkJ_KojuKwImF0G0CsTlxYTOU2sPsd5o1JDt65wGniQR2IZufnPbbK76Yh_KI2DY4cUxMfcb2fAXcFMc9dcpHg6f9wBXhUtFYTu6pi5LhhGuhpkiGcv6vWYNxMrpWJW_pV7q8mPilwkAP-zw5MJxkgijl2wDMpM-UUQ_k37FVtf-ndbQAIPG7S469doZMmb5IZYgvcB4ojqCW3Vz6Q
   

   If the captcha is not solved yet server will return CAPCHA_NOT_READY. Just repeat your request in 5 seconds.

   If something went wrong server will return an error. See Error Handling chapter for the list of errors.

   Sample request:

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   https://api.bigcaptcha.com/res.php?key=1abc234de56fab7c89012d34e56fa7b8&action=get&json=1&id=2122988149
   

7. After receiving the token from our API you’ve got to use it properly on the target website. Best way to understant that is to check the requests sent to site when you act as a normal user. Most browsers has developer’s console tool where you should check Network tab.Usually token is sent using POST request. It could be g-recaptcha-response just like reCAPTCHA V2 does or g-recaptcha-response-100000. It could be other parameter too. So you’ve got to inspect the requests and find out how exactly the token supposed to be sent. Then you have to compose your request accordingly.
8. Now when you have successfully submit the token you may tell us if it worked or not. If not we will refund the money you spent on this token. If it was successfully accepted we will set the worker who solved this captcha as the priority solver for you. Besides we will gather statistics regarding V3 solution which will help us to further investigate this new type of captchas and make our service better.To let us know whether it worked or not please send the request to https://api.bigcaptcha.com/res.php with your API Key in key parameter with ID of the captcha in id parameter and indicating action parameter. Next to mention is reportgood if token was accepted successfully or reportbad if token wasn’t accepted respectfully.

Request examples:

ReportBAD

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https://2captcha.com/res.php?key=1abc234de56fab7c89012d34e56fa7b8&action=reportbad&id=2122988149

ReportGOOD

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https://api.bigcaptcha.com/res.php?key=1abc234de56fab7c89012d34e56fa7b8&action=reportgood&id=2122988149

Important: complains for captcha types solved with token are not shown on the website. But we proceed with every report and gather the statistics. We will implement this complain display feature in future.

List of GET/POST request parameters for https://api.bigcaptcha.com/in.php

List of GET request parameters for https://api.bigcaptcha.com/res.php

The method is pretty simple:

1. You need to locate two values on the page with Funcaptcha
   • – Public key
   • – Service URL (surl)

   Public key can be found inside data-pkey parameter of funcaptcha’s div element or inside an input element with name fc-token – just extract the key indicated after pk from the value of this element.
   Service Url can be also found in fc-token – that is a value of surl parameter.
   Service Url is optional parameter and if you don’t provide it we use a default value that is valid for most cases, but we recommend you to provide it.

2. Submit a HTTP GET or POST request to our API URL: https://api.bigcaptcha.com/in.php with method set to funcaptcha, provide values found on previous step for publickey and surl parameter and full page URL as value for pageurl.
   You can find the full list of parameters in the table below.
   Request URL example:

   Copy to Clipboard
   https://api.bigcaptcha.com/in.php?key=1abc234de56fab7c89012d34e56fa7b8&method=funcaptcha&publickey=12AB34CD-56F7-AB8C-9D01-2EF3456789A0&surl=https://client-api.arkoselabs.com&pageurl=http://mysite.com/page/with/funcaptcha/
   

3. If everything is fine server will return the ID of your captcha as plain text, like: OK|2122988149 or as JSON {“status”:1,”request”:”2122988149″} if json parameter was used.
   Otherwise server will return an error code.
4. Make a 10-20 seconds timeout then submit a HTTP GET request to our API URL: https://api.bigcaptcha.com/res.php to get the result.
   The full list of parameters is in the table below.If captcha is already solved server will respond in plain text or JSON and return the answer token that looks like:

   3084f4a302b176cd7.96368058|r=ap-southeast-1|guitextcolor=%23FDD531|metabgclr=%23FFFFFF|metaiconclr=%23202122|meta=3|lang=en|pk=12AB34CD-56F7-AB8C-9D01-2EF3456789A0|cdn_url=https://cdn.funcaptcha.com/fc|surl=https://funcaptcha.com
   

   If captcha is not solved yet server will return CAPCHA_NOT_READY result. Repeat your request in 5 seconds.

   If something went wrong server will return an error code.

5. Locate the element with id fc-token and put the token into value of this element.
6. Do the rest what you need to do on the website: submit a form or click on a button or something else.

List of GET/POST request parameters for https://api.bigcaptcha.com/in.php

List of GET request parameters for https://api.bigcaptcha.com/res.php

Request URL example:

https://api.bigcaptcha.com/res.php?key=1abc234de56fab7c89012d34e56fa7b8&action=get&id=2122988149

Sometimes it can be hard to find to undrestand why our API returns an error code when you make a request that looks correct.

We provide a debugging method that can help you to find the root of the problem showing what exactly our API recevied from you.

The method can be used both on in.php and res.php API endpoints for any request.

Add an additional parameter debug_dump=1 to your request and our server will return a dump of request parameters that received by our API.

Request example:

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https://api.bigcaptcha.com/in.php?key=1abc234de56fab7c89012d34e56fa7b8&method=userrecaptcha&googlekey=6Le-wvkSVVABCPBMRTvw0Q4Muexq1bi0DJwx_mJ-&json=1&header_acao=1&pageurl=http://mysite.com/page/with/recaptcha/&pingback=http://1.2.3.4/pingback_handler/&debug_dump=1

Response example:

array(8) {
["key"]=>
string(32) "1abc234de56fab7c89012d34e56fa7b8"
["method"]=>
string(13) "userrecaptcha"
["googlekey"]=>
string(40) "6Le-wvkSVVABCPBMRTvw0Q4Muexq1bi0DJwx_mJ-"
["json"]=>
string(1) "1"
["header_acao"]=>
string(1) "1"
["pageurl"]=>
string(38) "http://mysite.com/page/with/recaptcha/"
["pingback"]=>
string(32) "http://1.2.3.4/pingback_handler/"
["debug_dump"]=>
string(1) "1"
}
array(0) {
}
array(0) {
}
{"status":0,"request":"ERROR_KEY_DOES_NOT_EXIST"}

Using this method you will be able to easily identify cases when your request contains invalid data or missing required parameters.