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Certbot is EFF's tool to obtain certs from Let's Encrypt and (optionally) auto-enable HTTPS on your server. It can also act as a client for any other CA that uses the ACME protocol.

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Rated 4.75 out of 5
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Statistics on certbot

Number of watchers on Github 21354
Number of open issues 949
Average time to close an issue 1 day
Main language Python
Average time to merge a PR 2 days
Open pull requests 215+
Closed pull requests 71+
Last commit about 1 year ago
Repo Created over 4 years ago
Repo Last Updated about 1 year ago
Size 17.5 MB
Organization / Authorcertbot
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.. This file contains a series of comments that are used to include sections of this README in other files. Do not modify these comments unless you know what you are doing. tag:intro-begin

Certbot is part of EFFs effort to encrypt the entire Internet. Secure communication over the Web relies on HTTPS, which requires the use of a digital certificate that lets browsers verify the identity of web servers (e.g., is that really Web servers obtain their certificates from trusted third parties called certificate authorities (CAs). Certbot is an easy-to-use client that fetches a certificate from Lets Encryptan open certificate authority launched by the EFF, Mozilla, and othersand deploys it to a web server.

Anyone who has gone through the trouble of setting up a secure website knows what a hassle getting and maintaining a certificate is. Certbot and Lets Encrypt can automate away the pain and let you turn on and manage HTTPS with simple commands. Using Certbot and Let's Encrypt is free, so theres no need to arrange payment.

How you use Certbot depends on the configuration of your web server. The best way to get started is to use our interactive guide <>. It generates instructions based on your configuration settings. In most cases, youll need root or administrator access <> to your web server to run Certbot.

If youre using a hosted service and dont have direct access to your web server, you might not be able to use Certbot. Check with your hosting provider for documentation about uploading certificates or using certificates issued by Lets Encrypt.

Certbot is a fully-featured, extensible client for the Let's Encrypt CA (or any other CA that speaks the ACME <>_ protocol) that can automate the tasks of obtaining certificates and configuring webservers to use them. This client runs on Unix-based operating systems.

To see the changes made to Certbot between versions please refer to our changelog <>_.

Until May 2016, Certbot was named simply letsencrypt or letsencrypt-auto, depending on install method. Instructions on the Internet, and some pieces of the software, may still refer to this older name.


If you'd like to contribute to this project please read Developer Guide <>_.

.. _installation:


The easiest way to install Certbot is by visiting, where you can find the correct installation instructions for many web server and OS combinations. For more information, see Get Certbot <>.


How to run the client

In many cases, you can just run certbot-auto or certbot, and the client will guide you through the process of obtaining and installing certs interactively.

For full command line help, you can type::

./certbot-auto --help all

You can also tell it exactly what you want it to do from the command line. For instance, if you want to obtain a cert for,, and, using the Apache plugin to both obtain and install the certs, you could do this::

./certbot-auto --apache -d -d -d

(The first time you run the command, it will make an account, and ask for an email and agreement to the Let's Encrypt Subscriber Agreement; you can automate those with --email and --agree-tos)

If you want to use a webserver that doesn't have full plugin support yet, you can still use standalone or webroot plugins to obtain a certificate::

./certbot-auto certonly --standalone --email -d -d -d

Understanding the client in more depth

To understand what the client is doing in detail, it's important to understand the way it uses plugins. Please see the explanation of plugins <>_ in the User Guide.


.. Do not modify this comment unless you know what you're doing. tag:links-begin


Software project:

Notes for developers:

Main Website:

Let's Encrypt Website:

IRC Channel: #letsencrypt on Freenode_


ACME spec:

ACME working area in github:

|build-status| |coverage| |docs| |container|

.. _Freenode:

.. |build-status| image:: :target: :alt: Travis CI status

.. |coverage| image:: :target: :alt: Coverage status

.. |docs| image:: :target: :alt: Documentation status

.. |container| image:: :target: :alt: Docker Repository on

.. Do not modify this comment unless you know what you're doing. tag:links-end

System Requirements


.. Do not modify this comment unless you know what you're doing. tag:intro-end

.. Do not modify this comment unless you know what you're doing. tag:features-begin

Current Features

  • Supports multiple web servers:

    • apache/2.x
    • nginx/0.8.48+
    • webroot (adds files to webroot directories in order to prove control of domains and obtain certs)
    • standalone (runs its own simple webserver to prove you control a domain)
    • other server software via third party plugins <>_
  • The private key is generated locally on your system.

  • Can talk to the Let's Encrypt CA or optionally to other ACME compliant services.

  • Can get domain-validated (DV) certificates.

  • Can revoke certificates.

  • Adjustable RSA key bit-length (2048 (default), 4096, ...).

  • Can optionally install a http -> https redirect, so your site effectively runs https only (Apache only)

  • Fully automated.

  • Configuration changes are logged and can be reverted.

  • Supports an interactive text UI, or can be driven entirely from the command line.

  • Free and Open Source Software, made with Python.

.. Do not modify this comment unless you know what you're doing. tag:features-end

For extensive documentation on using and contributing to Certbot, go to If you would like to contribute to the project or run the latest code from git, you should read our developer guide <>_.

certbot open issues Ask a question     (View All Issues)
  • over 2 years Rewrite our Dockerfile
  • over 2 years renew doesn't print a timestamp for logging purposes
  • over 2 years Test a real Certbot installation in the le_auto tests
  • over 2 years Bump pyopenssl version
  • over 2 years Make tests/ python 3 compliant
  • over 2 years Certbot apache module - how to have different SSL vhosts file with dummy cert
  • over 2 years Further merge --script-* with --*-hook
  • over 2 years Nginx integration tests
  • over 2 years certbot-auto Alpine support
  • over 2 years psutil versioning weirdness on Ubuntu 16.04
  • over 2 years Error install Python packages (UnicodeDecodeError)
  • over 2 years certbot doesn't use free ipv6 ports 80 and 443
  • over 2 years Strange reinstallation errors
  • over 2 years Generalize return types for plugin interfaces
  • over 2 years Possible Nginx if-statement weirdness
  • over 2 years Cli help is sometimes wrong about what the default for something is
  • over 2 years Remove sphinxcontrib-programoutput dependency?
  • over 2 years Python 2.6 deprecation warning for RHEL 6
  • over 2 years Stop using print
  • over 2 years cannot apache plugin RPM for RHEL 6/7
  • over 2 years Apache plugin error -- syntax error in configuration file
  • over 2 years Add full support for using an existing private key
  • over 2 years Get Certbot 0.9.3 or 0.10.0 into Xenial
  • over 2 years le-auto upgrading fails if virtualenv isn't installed
  • over 2 years certbot --help <subcommand>
  • over 2 years How to modify *-auto
  • over 2 years certbot-auto --apache fails to parse config
  • over 2 years Don't crash when U-label IDN provided on command line
  • over 2 years Common Name inconsistent with --webroot-map
  • over 2 years --dry-run and expiration e-mails
certbot open pull requests (View All Pulls)
  • New download instructions
  • Wiki migration
  • Ensure /usr/local/lib/ exists in bootstraper
  • Fixing for Python 2.6
  • Adding --gui argument
  • Release script prep
  • Randomize serial numbers of DVSNI challenge certificates. [needs revision]
  • Add a URL checker for docs in Travis.
  • Joyent SmartOS Zone Bootstrap Support [revised]
  • certbot-auto
  • Add privacy information to the Subscriber Agreement question
  • Deprecation warning for non-updating letsencrypt-auto
  • Proof-of-concept Heroku support
  • Rename of docs
  • Reuse HTTP connections.
  • Systemd /etc/os-release parsing for distribution fingerprinting
  • ACME: omitempty Error.detail, Error.type (fixes #2289)
  • Remove text wrapping
  • letsencrypt-auto --help now avoids bootstrapping
  • ignore EPERM when chown()ing dir for http-01
  • Nginx plugin map statement hotfix
  • treat ESC as cancel [needs revision]
  • IDisplay calls should also produce log entries [needs tests]
  • OCSP Stapling Enhancement for Apache
  • Update Dockerfile so that it uses the pip package
  • Fix symlink webroot paths
  • Refactor HelpfulArgumentParser homework (was: renew implies noninteractive earlier) [needs minor revision]
  • Expanding tests for le-auto, adding CentOS test suite [do not merge]
  • Add --must-staple flag
  • ECDSA subject key support
  • Autoconfigure OCSP Stapling with --must-staple
  • Displaying DialogError details correctly
  • -v implies --text
  • Fix FQDN checks, closes #3057 and #3056
  • Limiting tox envlist to really needed tests
  • Expanding tests for le-auto, adding Fedora 23 [need help]
  • Add --disable-hook-validation
  • Adding OS X 10.11 test to Travis [need help]
  • Typo: too many self's
  • Remove reference to letsencrypt-auto in error message [revision requested]
  • Remove dangling footnote
  • Don't call the default kwargs to atexit_print_messages
  • Make Docker changes to allow use in tests.
  • Use kill instead of killpg.
  • Add a register verb, with a way to update registrations [has suggested revisions]
  • Expanding tests for le-auto, adding Debian test suite
  • Do not install mod_ssl [needs revisions]
  • Expanding tests for le-auto, adding Ubuntu test suite
  • Added the argument --quiet and -q so then when used with a regular user there is no output to the screen.
  • Adding sensible UI logging for typical user
  • Prevent bootstrap-issue on Debian systems with virtualenv package
  • Mageia Bootstrap
  • Improve debug logs.
  • Improve user experience for linting.
  • Revert "Use --force-reinstall to fix bad virtualenv package"
  • Exit if cannot bootstrap in certbot-auto
  • Add code layout to contributing.rst
  • Improve non root error message
  • Log / explain when Apache is optimistically falling back to *:443 vhosts
  • Nginx space preservation
  • Issue 2983
  • Set dialog widgets to use autowidgetsize
  • Printing pip output to terminal when -v is used
  • Remove unnecessary check on registration returned.
  • Amazon CloudFront Usage issue #2539 closed
  • updating readme with free memory requirement [revised]
  • If Nginx does not found vhost info, does not create it
  • Takes position in site-config-file in consideration when removing dup…
  • No conflicting declarations
  • Make argparse dependency unconditional.
  • Auto creates a vhost configuration file if possible [needs revision]
  • New docs structure and introduction
  • [DO NOTE MERGE] avoid conflicting Nginx declarations
  • Update various package names in using.rst from "letsencrypt" to "certbot" [needs revision]
  • Nginx charset_map and ${VARIABLE_SUBSTITUTION} parsing
  • Use simple socket test for port availability if psutil not found [minor revisions requested]
  • Python 3 support for certonly
  • Set dialog widgets to use autowidgetsize
  • Automatically enable EPEL after prompting users
  • Multi-topic help listings [needs minor revision]
  • add -D/--webroot-delay-auth option
  • seth and noah updated some confusing things [revisions requested]
  • I restructured Installation and Using a bit
  • Update docs/contributing.rst to match display behavior during release.
  • Add standalone option for running a TLS server when validating HTTP-01 challenges
  • Fix update registration when ToS has changed
  • Add list-certs command
  • Specify archive directory in renewal configuration file
  • Fix link to Docker's user guide
  • Adding checking name validity to the Apache plugin
  • Add our logo to the docs [revision requested]
  • disallow binary (wheel) install for pycparser
  • Impelment account deactivation
  • Nginx compatibility test
  • Mention that the domain is used to choose filename
  • Add dnspython to dev dependencies
  • Mention Python venv setup in certbot-auto --help
  • Script plugin
  • #3510: Updating GUI with a note to use spacebar for select/deselect
  • #3355: Updated certbot-auto source files to check for free memory
  • Server alias
  • Explained what is standalone mode in the documentation for #3451
  • When getopts is called multiple time we need to reset OPTIND.
  • certbot-auto: Print link to doc on debugging pip install error [revision requested]
  • Testing the output of against lea-source/lea
  • changing to system-release [needs tweaking]
  • fix #3347 - quote domain name [needs revision]
  • Make return type of certbot.interfaces.IInstaller.get_all_keys_certs() an iterator
  • #3408: Made Gentoo bootstrapping asking before performing any changes
  • Multiple vhosts
  • Bind to IPv6, fix the problem of ipv6 site cannot generate / renew certificate [revision requested]
  • Clarification to confusing success message on manual re-installation [minor revision requested]
  • Fix writing pem files with Python3
  • Remove get_all_certs_keys() from
  • Don't re-add redirects if one exists
  • Fix OS Documentation
  • Allow notification interface to not wrap text
  • Add renew_hook to options stored in the renewal config, #3394
  • issue_3286: pointing people towards OS packages
  • Set Accept-Language header.
  • Add README file to each live directory explaining its contents.
  • Fail early if a selected enhancement is unsupported by the current pl… [revision requested]
  • Add IPv6 support to ACME standalone mode
  • Add note regarding cryptography dependency in contribution docs [revision requested]
  • [changes requested] Refactor and
  • Ensure tests pass with openssl 1.1
  • Fix for Python3
  • Add ability to reuse key during cert renewal (#3788)
  • Add bootstrapping of alpine deps
  • Take advantage of urllib3 pyopenssl rewrite
  • [revision requested] Busybox support
  • Implement the --cert-name flag to select a lineage by its name.
  • Changed plugin interface return types (#3748).
  • Add workaround for platforms where injecting pyopenssl to urllib3 fails with requests package (Ubuntu Trusty) [revision requested]
  • Silence Package Manager Output when certbot-auto invoked with --quiet [revision requested]
  • Fix example links
  • Package certbot-dns-google
  • Package certbot-dns-digitalocean
  • --certbot-dir is easier to set that --config-dir, --logs-dir, --work-dir
  • certbot-dns-cloudflare packaging
  • Update options-ssl-nginx.conf on new certbot version
  • Allow reuse of private keys
  • LuaDNS DNS Authenticator
  • DNS Made Easy DNS Authenticator
  • NS1 DNS Authenticator
  • DNSimple DNS Authenticator
  • CloudXNS DNS Authenticator
  • Common code for Lexicon-based DNS authenticators
  • Fixes the suggested python code to work with IPv4 & IPv6 installations
  • update cert to certificate
  • Be careful with new interaction from enabling nginx
  • Add Arch Linux constants for Apache
  • "What is a Certificate?" section first draft
  • [#4109] modifying revoke subcommand to include option to delete certs
  • Add flags to configure log rotation
  • [#3866]: "certbot certificates" checks validity with OpenSSL
  • Json certificate output (#3909)
  • Do not parse disabled configuration files from under sites-available on Debian / Ubuntu
  • Mention first domain = name in --help output
  • Added install-only flag
  • Fix Apache configurator test
  • Remove autodocs for long-removed acme.other module
  • Use "certificate" instead of "cert" in docs.
  • Fix test inconsistency in Apache plugin configurator_test
  • Dovecot parsed tree dumper [WIP]
  • Drop support for EOL Python 2.6 and 3.3
  • from botocore.exceptions import ClientError
  • Add sudo to certbot-auto instructions.
  • Use restart instead of graceful for certain distributions in Apache plugin
  • Only add Include for TLS configuration if not already there
  • Add acme library usage example (http-01)
  • Ignore .docker
  • PluginStorage to store variables between invocations.
  • Support Openresty in the NGINX plugin
  • feat(nginx plugin): add HSTS enhancement
  • Documentation on cron renewal
  • Certbot installer for Zimbra
  • Proper webroot directory cleanup
  • Add integration tests for nginx plugin
  • Cleanup dockerfile-dev
  • OVH DNS Authenticator
  • [Docs] restore docs for ppl just using Certbot git master
  • Update leauto_upgrades with tests from #5402
  • ACMEv2: Add Order support
  • Dovecot installer plugin
  • Overriding the default challenge domain in DNS authenticators
  • Use UTF-8 encoding for nginx plugin
  • Interfaces for TLS updates and plugin specific updates
  • Doc Structure Changes
  • Fix wildcard issuance
  • Nginx plugin wildcard support for ACMEv2
  • Apache plugin wildcard support for ACMEv2
  • logging: log timestamps as local timezone instead of UTC
  • Drop Python 2.6 and 3.3 support
  • Enhance verb
  • Fix print() and xrange() for Python 3
  • Add webroot url to warn message
  • Postfix plugin changes
  • Add Azure DNS auth [WIP]
  • Linode DNS Authenticator
  • certbot-auto-cron [#3522]
  • Feature/azure dns
  • Let certbot-auto work behind the Great Firewall of China. Fix #3222. Ref #4371.
  • Gehirn Infrastracture Service DNS Authenticator
  • Sakura Cloud DNS Authenticator
  • Put API link at the bottom of DNS plugin docs
  • Document resps parameter
  • Allow _acme-challenge in a separate zone
  • Update the changelog to reflect 0.22.0
  • Update the test-everything branch
  • Release 0.22.0
  • Improve "cannot find cert of key directive" error (#5525)
  • Also allow hostnames instead of just IP addresses
  • Improve style around choosing lineagename
  • make compatible with POSIX sh(1) again
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