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Awesome Open Source


Proxy server to bypass Cloudflare protection

⚠️ This project is in beta state. Some things may not work and the API can change at any time. See the known issues section.

How it works

FlareSolverr starts a proxy server and it waits for user requests in an idle state using few resources. When some request arrives, it uses puppeteer with the stealth plugin to create a headless browser (Chrome). It opens the URL with user parameters and waits until the Cloudflare challenge is solved (or timeout). The HTML code and the cookies are sent back to the user and those cookies can be used to bypass Cloudflare using other HTTP clients.

NOTE: Web browsers consume a lot of memory. If you are running FlareSolverr on a machine with few RAM, do not make many requests at once. With each request a new browser is launched. (It is possible to use a permanent session. However, if you use sessions, you should make sure to close them as soon as you are done using them.)


It requires NodeJS.

Run PUPPETEER_PRODUCT=chrome npm install to install FlareSolverr dependencies.


First run npm run build. Once the TypeScript is compiled, you can use npm start to start FlareSolverr.

Example request:

curl -L -X POST 'http://localhost:8191/v1' \
-H 'Content-Type: application/json' \
--data-raw '{
  "cmd": "request.get",
  "userAgent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.138 Safari/537.36",
  "maxTimeout": 60000,
  "headers": {
    "X-Test": "Testing 123..."


+ sessions.create

This will launch a new browser instance which will retain cookies until you destroy it with sessions.destroy. This comes in handy so you don't have to keep solving challenges over and over and you won't need to keep sending cookies for the browser to use.

This also speeds up the requests since it won't have to launch a new browser instance for every request.

Parameter Notes
session Optional. The session ID that you want to be assinged to the instance. If one isn't set a random UUID will be assigned.
userAgent Optional. Will be used by the headless browser.

+ sessions.list

Returns a list of all the active sessions. More for debuging if you are curious to see how many sessions are running. You should always make sure to properly close each session when you are done using them as too many may slow your computer down.

Example response:

  "sessions": [

+ sessions.destroy

This will properly shutdown a browser instance and remove all files associaded with it to free up resources for a new session. Whenever you no longer need to use a session you should make sure to close it.

Parameter Notes
session The session ID that you want to be destroyed.

+ request.get

Parameter Notes
url Mandatory
session Optional. Will send the request from and existing browser instance. If one is not sent it will create a temporary instance that will be destroyed immediately after the request is completed.
headers Optional. To specify user headers.
maxTimeout Optional. Max timeout to solve the challenge
cookies Optional. Will be used by the headless browser. Follow this format

Example response from running the curl above:

    "solution": {
        "url": "",
        "status": 200,
        "headers": {
            "status": "200",
            "date": "Thu, 16 Jul 2020 04:15:49 GMT",
            "expires": "-1",
            "cache-control": "private, max-age=0",
            "content-type": "text/html; charset=UTF-8",
            "strict-transport-security": "max-age=31536000",
            "p3p": "CP=\"This is not a P3P policy! See for more info.\"",
            "content-encoding": "br",
            "server": "gws",
            "content-length": "61587",
            "x-xss-protection": "0",
            "x-frame-options": "SAMEORIGIN",
            "set-cookie": "1P_JAR=2020-07-16-04; expires=Sat, 15-Aug-2020 04:15:49 GMT; path=/;; Secure; SameSite=none\nNID=204=QE3Ocq15XalczqjuDy52HeseG3zAZuJzID3R57g_oeQHyoV5DuvDhpWc4r9IcPoeIYmkr_ZTX_MNOU8IAbtXmVO7Bmq0adb-hpIHaTBIdBk3Ofifp4gO6vZleVuFYfj7ePkHeHdzGoX-en0FvKtd9iofX4O6RiAdEIAnpL7Wge4; expires=Fri, 15-Jan-2021 04:15:49 GMT; path=/;; Secure; HttpOnly; SameSite=none",
            "alt-svc": "h3-29=\":443\"; ma=2592000,h3-27=\":443\"; ma=2592000,h3-25=\":443\"; ma=2592000,h3-T050=\":443\"; ma=2592000,h3-Q050=\":443\"; ma=2592000,h3-Q046=\":443\"; ma=2592000,h3-Q043=\":443\"; ma=2592000,quic=\":443\"; ma=2592000; v=\"46,43\""
        "response":"<!DOCTYPE html>...",
        "cookies": [
                "name": "NID",
                "value": "204=QE3Ocq15XalczqjuDy52HeseG3zAZuJzID3R57g_oeQHyoV5DuvDhpWc4r9IcPoeIYmkr_ZTX_MNOU8IAbtXmVO7Bmq0adb-hpIHaTBIdBk3Ofifp4gO6vZleVuFYfj7ePkHeHdzGoX-en0FvKtd9iofX4O6RiAdEIAnpL7Wge4",
                "domain": "",
                "path": "/",
                "expires": 1610684149.307722,
                "size": 178,
                "httpOnly": true,
                "secure": true,
                "session": false,
                "sameSite": "None"
                "name": "1P_JAR",
                "value": "2020-07-16-04",
                "domain": "",
                "path": "/",
                "expires": 1597464949.307626,
                "size": 19,
                "httpOnly": false,
                "secure": true,
                "session": false,
                "sameSite": "None"
        "userAgent": "Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.138 Safari/537.36"
    "status": "ok",
    "message": "",
    "startTimestamp": 1594872947467,
    "endTimestamp": 1594872949617,
    "version": "1.0.0"


This is the same as request.get but it takes one more param:

Parameter Notes
postData Must be a string. If you want to POST a form, don't forget to set the Content-Type header to application/x-www-form-urlencoded or the server might not understand your request.

Downloading Images and PDFs (small files)

If you need to access an image/pdf or small file, you should pass the download parameter to request.get setting it to true. Rather than access the html and return text it will return a the buffer base64 encoded which you will be able to decode and save the image/pdf.

This method isn't recommended for videos or anything larger. As that should be streamed back to the client and at the moment there is nothing setup to do so. If this is something you need feel free to create an issue and/or submit a PR.

Environment variables

To set the environment vars in Linux run export LOG_LEVEL=debug and then start FlareSolverr in the same shell.

Name Default Notes
LOG_LEVEL info Used to change the verbosity of the logging.
LOG_HTML false Used for debugging. If true all html that passes through the proxy will be logged to the console.
PORT 8191 Change this if you already have a process running on port 8191.
HOST This shouldn't need to be messed with but if you insist, it's here!
CAPTCHA_SOLVER None This is used to select which captcha solving method it used when a captcha is encounted.
HEADLESS true This is used to debug the browser by not running it in headless mode.

Captcha Solvers

Sometimes CF not only gives mathmatical computations and browser tests, sometimes they also require the user to solve a captcha. If this is the case, FlareSolverr will return the captcha page. But that's not very helpful to you is it?

FlareSolverr can be customized to solve the captcha's automatically by setting the environment variable CAPTCHA_SOLVER to the file name of one of the adapters inside the /captcha directory.


This method makes use of the CaptchaHarvester project which allows users to collect thier own tokens from ReCaptcha V2/V3 and hCaptcha for free.

To use this method you must set these ENV variables:


Note: above I set HARVESTER_ENDPOINT to the default configureation of the captcha harvester's server, but that could change if you customize the command line flags. Simply put, HARVESTER_ENDPOINT should be set to the URI of the route that returns a token in plain text when called.


This method makes use of the hcaptcha-solver project which attempts to solve hcaptcha by randomly selecting images.

To use this solver you must first install it and then set it as the CAPTCHA_SOLVER.

npm i hcaptcha-solver


You can edit environment variables in ./Dockerfile and build your own image.

docker build -t flaresolverr:latest .
docker run --restart=always --name flaresolverr -p 8191:8191 -d flaresolverr:latest


I'm quite new to TypeScript. If you spot any funny business or anything that is or isn't being used properly feel free to submit a PR or open an issue.

Known issues / Roadmap

The current implementation seems to be working on the sites I have been testing them on. However, if you find it unable to access a site, open an issue and I'd be happy to investigate.

That being said, the project uses the puppeteer stealth plugin. If Cloudflare is able to detect the headless browser, it's more that projects domain to fix.


  • Fix remaining issues in the code (see TODOs in code)
  • Make the maxTimeout more accurate (count the time to open the first page / maybe count the captcha solve time?)
  • Hide sensitive information in logs
  • Reduce Docker image size
  • Docker image for ARM architecture
  • Install instructions for Windows

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