https://github.com/FiloSottile/mkcert
 

mkcert

mkcert is a simple tool for making locally-trusted development certificates. It requires no configuration.
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Using certificates from real certificate authorities (CAs) for development can be dangerous or impossible (for hosts like example.test, localhost or 127.0.0.1), but self-signed certificates cause trust errors. Managing your own CA is the best solution, but usually involves arcane commands, specialized knowledge and manual steps.
mkcert automatically creates and installs a local CA in the system root store, and generates locally-trusted certificates. mkcert does not automatically configure servers to use the certificates, though, that's up to you.

Installation

macOS

On macOS, use Homebrew
or MacPorts.

Linux

On Linux, first install certutil.
Then you can install using Homebrew on Linux
or build from source (requires Go 1.13+)
or use the pre-built binaries.
For Arch Linux users, mkcert is available on the official Arch Linux repository.

Windows

On Windows, use Chocolatey
or use Scoop
or build from source (requires Go 1.10+), or use the pre-built binaries.
If you're running into permission problems try running mkcert as an Administrator.

Supported root stores

mkcert supports the following root stores:
  • macOS system store
  • Windows system store
  • Linux variants that provide either
    • update-ca-trust (Fedora, RHEL, CentOS) or
    • update-ca-certificates (Ubuntu, Debian, OpenSUSE, SLES) or
    • trust (Arch)
  • Firefox (macOS and Linux only)
  • Chrome and Chromium
  • Java (when JAVA_HOME is set)
To only install the local root CA into a subset of them, you can set the TRUST_STORES environment variable to a comma-separated list. Options are: "system", "java" and "nss" (includes Firefox).

Advanced topics

Advanced options

Example

S/MIME

mkcert automatically generates an S/MIME certificate if one of the supplied names is an email address.

Mobile devices

For the certificates to be trusted on mobile devices, you will have to install the root CA. It's the rootCA.pem file in the folder printed by mkcert -CAROOT.
On iOS, you can either use AirDrop, email the CA to yourself, or serve it from an HTTP server. After opening it, you need to install the profile in Settings > Profile Downloaded and then enable full trust in it.
For Android, you will have to install the CA and then enable user roots in the development build of your app. See this StackOverflow answer.

Using the root with Node.js

Node does not use the system root store, so it won't accept mkcert certificates automatically. Instead, you will have to set the NODE_EXTRA_CA_CERTS environment variable.

Changing the location of the CA files

The CA certificate and its key are stored in an application data folder in the user home. You usually don't have to worry about it, as installation is automated, but the location is printed by mkcert -CAROOT.
If you want to manage separate CAs, you can use the environment variable $CAROOT to set the folder where mkcert will place and look for the local CA files.

Installing the CA on other systems

Installing in the trust store does not require the CA key, so you can export the CA certificate and use mkcert to install it in other machines.
  • Look for the rootCA.pem file in mkcert -CAROOT
  • copy it to a different machine
  • set $CAROOT to its directory
  • run mkcert -install
Remember that mkcert is meant for development purposes, not production, so it should not be used on end users' machines, and that you should not export or share rootCA-key.pem.