pip install gensim config --global http.sslVerify false

Just install any package with the "config --global http.sslVerify false" statement

You can ignore SSL errors by setting pypi.org and files.pythonhosted.org as well as the older pypi.python.org as trusted hosts.

$ pip install --trusted-host pypi.org --trusted-host pypi.python.org --trusted-host files.pythonhosted.org <package_name>

Note: Sometime during April 2018, the Python Package Index was migrated from pypi.python.org to pypi.org. This means "trusted-host" commands using the old domain no longer work, but you can add both.

Permanent Fix

Since the release of pip 10.0, you should be able to fix this permanently just by upgrading pip itself:

$ pip install --trusted-host pypi.org --trusted-host pypi.python.org --trusted-host files.pythonhosted.org pip setuptools

Or by just reinstalling it to get the latest version:

$ curl  -o get-pip.py

(… and then running get-pip.py with the relevant Python interpreter).

pip install <otherpackage> should just work after this. If not, then you will need to do more, as explained below.

You may want to add the trusted hosts and proxy to your config file.

pip.ini (Windows) or pip.conf (unix)

[global]
trusted-host = pypi.python.org
               pypi.org
               files.pythonhosted.org

Alternate Solutions (Less secure)

Most of the answers could pose a security issue.

Two of the workarounds that help in installing most of the python packages with ease would be:

• Using easy_install: if you are really lazy and don't want to waste much time, use easy_install <package_name>. Note that some packages won't be found or will give small errors.
• Using Wheel: download the Wheel of the python package and use the pip command pip install wheel_package_name.whl to install the package.

You can specify a cert with this param:

pip --cert /etc/ssl/certs/FOO_Root_CA.pem install linkchecker

See: Docs » Reference Guide » pip

If specifying your company's root cert doesn't work maybe the cURL one will work:

You must use a PEM file and not a CRT file. If you have a CRT file you will need to convert the file to PEM There are reports in the comments that this now works with a CRT file but I have not verified.

Also check: SSL Cert Verification.

For me the problem was fixed by creating a folder pip, with a file: pip.ini in C:\Users\<username>\AppData\Roaming\ e.g:

C:\Users\<username>\AppData\Roaming\pip\pip.ini

Inside it I wrote:

[global]
trusted-host = pypi.python.org
               pypi.org
               files.pythonhosted.org

I restarted python, and then pip permanently trusted these sites, and used them to download packages from.

If you can't find the AppData Folder on windows, write %appdata% in file explorer and it should appear.

kenorb’s answer is very useful (and great!).
Among his solutions, maybe this is the most simple one: --trusted-host

For example, in this case you can do

pip install --trusted-host pypi.python.org linkchecker

The pem file(or anything else) is unnecessary.

The answers are quite similar and a bit confusing. In my case, the certificates in my company's network was the issue. I was able to work around the problem using:

pip install --trusted-host files.pythonhosted.org --trusted-host pypi.org --trusted-host pypi.python.org oauthlib -vvv

As seen here. The -vvv argument can be omited if verbose output is not required

Permanent Fix

pip install --upgrade pip --trusted-host pypi.org --trusted-host files.pythonhosted.org

For eg:

pip install <package name> --trusted-host pypi.org --trusted-host files.pythonhosted.org

I tried majority of the solutions provided in this answer blog, however none of them worked, I had this ssl certificant error as I try to install python packages.

I succeed by following command:

python -m pip install PACKAGENAME --trusted-host=pypi.python.org --trusted-host=pypi.org --trusted-host=files.pythonhosted.org 

Netscope related SSL issue on Windows 10 with Python 3.9

I had ssl issues due to company network security related to netscope. My machine is windows 10 with python 3.9 and the following command worked for me.

pip config set global.trusted-host "pypi.org files.pythonhosted.org pypi.python.org" --trusted-host=pypi.python.org --trusted-host=pypi.org --trusted-host=files.pythonhosted.org

Here, pip permanently trusted these sites, and now we can use them to download any packages.

The most straightforward way I've found, is to download and use the "DigiCert High Assurance EV Root CA" from DigiCert at

You can visit to verify the cert issuer by clicking on the lock icon in the address bar, or increase your geek cred by using openssl:

$ openssl s_client -connect pypi.python.org:443
CONNECTED(00000003)
depth=1 /C=US/O=DigiCert Inc/OU= SHA2 Extended Validation Server CA
verify error:num=20:unable to get local issuer certificate
verify return:0
---
Certificate chain
 0 s:/businessCategory=Private Organization/1.3.6.1.4.1.311.60.2.1.3=US/1.3.6.1.4.1.311.60.2.1.2=Delaware/serialNumber=3359300/street=16 Allen Rd/postalCode=03894-4801/C=US/ST=NH/L=Wolfeboro,/O=Python Software Foundation/CN=
   i:/C=US/O=DigiCert Inc/OU= SHA2 Extended Validation Server CA
 1 s:/C=US/O=DigiCert Inc/OU= SHA2 Extended Validation Server CA
   i:/C=US/O=DigiCert Inc/OU= High Assurance EV Root CA

The last CN value in the certificate chain is the name of the CA that you need to download.

For a one-off effort, do the following:

1. Download the CRT from DigiCert
2. Convert the CRT to PEM format
3. Export the PIP_CERT environment variable to the path of the PEM file

(the last line assumes you are using the bash shell) before running pip.

curl -sO  
openssl x509 -inform DES -in DigiCertHighAssuranceEVRootCA.crt -out DigiCertHighAssuranceEVRootCA.pem -text
export PIP_CERT=`pwd`/DigiCertHighAssuranceEVRootCA.pem

To make this re-usable, put DigiCertHighAssuranceEVRootCA.crt somewhere common and export PIP_CERT accordingly in your ~/.bashrc.

To solve this problem once and for all, you can verify that you have a pip.conf file.

This is where your pip.conf should be, according to the documentation:

On Unix the default configuration file is: $HOME/.config/pip/pip.conf which respects the XDG_CONFIG_HOME environment variable.

On macOS the configuration file is $HOME/Library/Application Support/pip/pip.conf if directory $HOME/Library/Application Support/pip exists else $HOME/.config/pip/pip.conf

On Windows the configuration file is %APPDATA%\pip\pip.ini.

Inside a virtualenv:

On Unix and macOS the file is $VIRTUAL_ENV/pip.conf

On Windows the file is: %VIRTUAL_ENV%\pip.ini

Your pip.conf should look like:

[global]
trusted-host = pypi.python.org

pip install linkchecker installed linkchecker without complains after I created the pip.conf file.

You've the following possibilities to solve issue with CERTIFICATE_VERIFY_FAILED:

• Use HTTP instead of HTTPS (e.g. --index-url=).

• Use --cert <trusted.pem> or CA_BUNDLE variable to specify alternative CA bundle.

  E.g. you can go to failing URL from web-browser and import root certificate into your system.

• Run python -c "import ssl; print(ssl.get_default_verify_paths())" to check the current one (validate if exists).

• OpenSSL has a pair of environments (SSL_CERT_DIR, SSL_CERT_FILE) which can be used to specify different certificate database^PEP-476.
• Use --trusted-host <hostname> to mark the host as trusted.
• In Python use verify=False for requests.get (see: SSL Cert Verification).
• Use --proxy <proxy> to avoid certificate checks.

Read more at: TLS/SSL wrapper for socket objects - Verifying certificates.

Set Time and Date correct!

For me, it came out that my date and time was misconfigured on Raspberry Pi. The result was that all SSL and HTTPS connections failed, using the server.

Update it like this:

sudo date -s "Wed Thu  23 11:12:00 GMT+1 2018"
sudo dpkg-reconfigure tzdata

Or directly with e.g. Google's time:

Ref.:

sudo date -s "$(curl -s --head  | grep ^Date: | sed 's/Date: //g')"
sudo dpkg-reconfigure tzdata

I recently ran into this problem because of my company's web content filter that uses its own Certificate Authority so that it can filter SSL traffic. PIP doesn't seem to be using the system's CA certificates in my case, producing the error you mention. Downgrading PIP to version 1.2.1 presented its own set of problems later on, so I went back to the original version that came with Python 3.4.

My workaround is quite simple: use easy_install. Either it doesn't check the certs (like the old PIP version), or it knows to use the system certs because it works every time for me and I can still use PIP to uninstall packages installed with easy_install.

If that doesn't work and you can get access to a network or computer that doesn't have the issue, you could always setup your own personal PyPI server: how to create local own pypi repository index without mirror?

I almost did that until I tried using easy_install as a last ditch effort.

You can try to bypass the SSL error by using http instead of https. Of course this is not optimal in terms of security, but if you are in a hurry it should do the trick:

pip install --index-url= linkchecker

TLDR:

pip install --trusted-host pypi.org --trusted-host pypi.python.org --trusted-host files.pythonhosted.org -r requirements.txt -vvv

pip install --trusted-host pypi.org --trusted-host pypi.python.org --trusted-host files.pythonhosted.org <packageName> -vvv

So, Having 30+ answers to the question already, but nothing was working for me in June 2020 (while in lockdown ).
all were given in different moments of past. I will try to make this answer work for all times in future. The problem is while pip installs package it tries to connect with host URL where package is stored and doesn't trust the URL while downloading it.

There are two ways we can solve this: Easy and non-secure: 1. check which URL is hit by pip to download the package.

pip install <packageName> -vvv

if you will carefully check the output, you will see it might be going to some URL like pypi.org or may be pypi.python.org.

if it is, just add trusted host option to the command like below:

pip install --trusted-host pypi.org --trusted-host pypi.python.org --trusted-host files.pythonhosted.org <packageName> -vvv

or if you are using requirements file:

pip install --trusted-host pypi.org --trusted-host pypi.python.org --trusted-host files.pythonhosted.org -r requirements.txt -vvv

Secure way:

Go to each of these URL and download their public cert (just google how to download), create a chain, store it as .pem file and run below command:

pip --cert YourPemFile.pem install <packageName>

I installed pip 1.2.1 with easy_install and upgraded to latest version of pip (6.0.7 at the time) which is able to install packages in my case.

easy_install pip==1.2.1
pip install --upgrade pip

The answers to use

pip install --trusted-host pypi.python.org <package>

work. But you'll have to check if there are redirects or caches pip is hitting. On Windows 7 with pip 9.0.1, I had to run

pip install \
  --trusted-host pypi.python.org \
  --trusted-host pypi.org \
  --trusted-host files.pythonhosted.org \
  <package>

You can find these with the verbose flag.

You have 4 options:

Using a certificate as parameter

$ pip install --cert /path/to/mycertificate.crt linkchecker

Using a certificate in a pip.conf

Create this file:

$HOME/.pip/pip.conf (Linux)

%HOME%\pip\pip.ini (Windows)

and add these lines:

[global]
cert = /path/to/mycertificate.crt

Ignoring certificate and using HTTP

$ pip install --trusted-host pypi.python.org linkchecker

Ignoring certificate and using HTTP in a pip.conf

Create this file:

$HOME/.pip/pip.conf (Linux)

%HOME%\pip\pip.ini (Windows)

and add these lines:

[global]
trusted-host = pypi.python.org

Source

First of all,

    pip install --trusted-host pypi.python.org <package name>

did not work for me. I kept getting the CERTIFICATE_VERIFY_FAILED error. However, I noticed in the error messages that they referenced the 'pypi.org' site. So, I used this as the trusted host name instead of pypi.python.org. That almost got me there; the load was still failing with CERTIFICATE_VERIFY_FAILED, but at a later point. Finding the reference to the website that was failing, I included it as a trusted host. What eventually worked for me was:

    pip install --trusted-host pypi.org --trusted-host files.pythonhosted.org <package name>

Had the same problem trying pip install ftputil with ActivePython 2.7.8, ActivePython 3.4.1, and "stock" Python 3.4.2 on 64-bit Windows 7 Enterprise. All attempts failed with the same errors as OP.

Worked around the problem for Python 3.4.2 by downgrading to pip 1.2.1: easy_install pip==1.2.1 (see ). Same fix also worked for ActivePython 2.7.8.

The bug, reported in March 2013, is still open: .