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FlareSolverr is a proxy server to bypass Cloudflare and DDoS-GUARD protection.

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 (Firefox). 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 also 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 is recommended to install using a Docker container because the project depends on an external browser that is already included within the image.

Docker images are available in:

Supported architectures are: | Architecture | Tag | | :----: | --- | | x86-64 | linux/amd64 | | ARM64 | linux/arm64 | | ARM32 | linux/arm/v7 |

We provide a docker-compose.yml configuration file. Clone this repository and execute docker-compose up -d to start the container.

If you prefer the docker cli execute the following command.

docker run -d \
  --name=flaresolverr \
  -p 8191:8191 \
  -e LOG_LEVEL=info \
  --restart unless-stopped \

If your host OS is Debian, make sure libseccomp2 version is 2.5.x. You can check the version with sudo apt-cache policy libseccomp2 and update the package with sudo apt install libseccomp2=2.5.1-1~bpo10+1 or sudo apt install libseccomp2=2.5.1-1+deb11u1. Remember to restart the Docker daemon and the container after the update.

Precompiled binaries

This is the recommended way for Windows users.

  • Download the FlareSolverr zip from the release's assets. It is available for Windows and Linux.
  • Extract the zip file. FlareSolverr executable and firefox folder must be in the same directory.
  • Execute FlareSolverr binary. In the environment variables section you can find how to change the configuration.

From source code

This is the recommended way for macOS users and for developers.

  • Install NodeJS 16.
  • Clone this repository and open a shell in that path.
  • Run export PUPPETEER_PRODUCT=firefox (Linux/macOS) or set PUPPETEER_PRODUCT=firefox (Windows).
  • Run npm install command to install FlareSolverr dependencies.
  • Run npm start command to compile TypeScript code and start FlareSolverr.

If you get errors related to firefox not installed try running node node_modules/puppeteer/install.js to install Firefox.

Systemd service

We provide an example Systemd unit file flaresolverr.service as reference. You have to modify the file to suit your needs: paths, user and environment variables.


Example request:

curl -L -X POST 'http://localhost:8191/v1' \
-H 'Content-Type: application/json' \
--data-raw '{
  "cmd": "request.get",
  "maxTimeout": 60000


+ 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 assigned to the instance. If isn't set a random UUID will be assigned.
proxy Optional, default disabled. Eg: "proxy": {"url": ""}. You must include the proxy schema in the URL: http://, socks4:// or socks5://. Authorization (username/password) is not supported.

+ sessions.list

Returns a list of all the active sessions. More for debugging 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 associated with it to free up resources for a new session. When 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.
maxTimeout Optional, default value 60000. Max timeout to solve the challenge in milliseconds.
cookies Optional. Will be used by the headless browser. Follow this format.
returnOnlyCookies Optional, default false. Only returns the cookies. Response data, headers and other parts of the response are removed.
proxy Optional, default disabled. Eg: "proxy": {"url": ""}. You must include the proxy schema in the URL: http://, socks4:// or socks5://. Authorization (username/password) is not supported. (When the session parameter is set, the proxy is ignored; a session specific proxy can be set in sessions.create.)

⚠️ If you want to use Cloudflare clearance cookie in your scripts, make sure you use the FlareSolverr User-Agent too. If they don't match you will see the challenge.

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..."
        "response":"<!DOCTYPE html>...",
        "cookies": [
                "name": "NID",
                "value": "204=QE3Ocq15XalczqjuDy52HeseG3zAZuJzID3R57...",
                "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/5..."
    "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 with application/x-www-form-urlencoded. Eg: a=b&c=d

Environment variables

Name Default Notes
LOG_LEVEL info Verbosity of the logging. Use LOG_LEVEL=debug for more information.
LOG_HTML false Only for debugging. If true all HTML that passes through the proxy will be logged to the console in debug level.
CAPTCHA_SOLVER none Captcha solving method. It is used when a captcha is encountered. See the Captcha Solvers section.
TZ UTC Timezone used in the logs and the web browser. Example: TZ=Europe/London.
HEADLESS true Only for debugging. To run the web browser in headless mode or visible.
BROWSER_TIMEOUT 40000 If you are experiencing errors/timeouts because your system is slow, you can try to increase this value. Remember to increase the maxTimeout parameter too.
TEST_URL FlareSolverr makes a request on start to make sure the web browser is working. You can change that URL if it is blocked in your country.
PORT 8191 Listening port. You don't need to change this if you are running on Docker.
HOST Listening interface. You don't need to change this if you are running on Docker.

Environment variables are set differently depending on the operating system. Some examples:

  • Docker: Take a look at the Docker section in this document. Environment variables can be set in the docker-compose.yml file or in the Docker CLI command.
  • Linux: Run export LOG_LEVEL=debug and then start FlareSolverr in the same shell.
  • Windows: Open cmd.exe, run set LOG_LEVEL=debug and then start FlareSolverr in the same shell.

Captcha Solvers

⚠️ At this time none of the captcha solvers work. You can check the status in the open issues. Any help is welcome.

Sometimes CloudFlare not only gives mathematical computations and browser tests, sometimes they also require the user to solve a captcha. If this is the case, FlareSolverr will return the error Captcha detected but no automatic solver is configured.

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

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