diff --git a/cli/__snapshots__/download_spec.js b/cli/__snapshots__/download_spec.js
index 1d1e063a4a67..e5a519fa9e94 100644
--- a/cli/__snapshots__/download_spec.js
+++ b/cli/__snapshots__/download_spec.js
@@ -17,7 +17,9 @@ https://cypress.example.com/desktop/0.20.2?platform=OS&arch=ARCH
 exports['download status errors 1'] = `
 Error: The Cypress App could not be downloaded.
 
-Please check network connectivity and try again:
+Does your workplace require a proxy to be used to access the Internet? If so, you must configure the HTTP_PROXY environment variable before downloading Cypress. Read more: https://on.cypress.io/proxy-configuration
+
+Otherwise, please check network connectivity and try again:
 
 ----------
 
diff --git a/cli/lib/errors.js b/cli/lib/errors.js
index 3727c7014ef3..1a83b96ce434 100644
--- a/cli/lib/errors.js
+++ b/cli/lib/errors.js
@@ -19,7 +19,10 @@ const hr = '----------'
 // common errors Cypress application can encounter
 const failedDownload = {
   description: 'The Cypress App could not be downloaded.',
-  solution: 'Please check network connectivity and try again:',
+  solution: stripIndent`
+  Does your workplace require a proxy to be used to access the Internet? If so, you must configure the HTTP_PROXY environment variable before downloading Cypress. Read more: https://on.cypress.io/proxy-configuration
+
+  Otherwise, please check network connectivity and try again:`,
 }
 
 const failedUnzip = {
diff --git a/cli/lib/tasks/download.js b/cli/lib/tasks/download.js
index 681c7cc39eb2..3bdda4ffd474 100644
--- a/cli/lib/tasks/download.js
+++ b/cli/lib/tasks/download.js
@@ -16,6 +16,16 @@ const util = require('../util')
 
 const defaultBaseUrl = 'https://download.cypress.io/'
 
+const getProxyUrl = () => {
+  return process.env.HTTPS_PROXY ||
+    process.env.https_proxy ||
+    process.env.npm_config_https_proxy ||
+    process.env.HTTP_PROXY ||
+    process.env.http_proxy ||
+    process.env.npm_config_proxy ||
+    null
+}
+
 const getRealOsArch = () => {
   // os.arch() returns the arch for which this node was compiled
   // we want the operating system's arch instead: x64 or x86
@@ -174,13 +184,19 @@ const verifyDownloadedFile = (filename, expectedSize, expectedChecksum) => {
 // {filename: ..., downloaded: true}
 const downloadFromUrl = ({ url, downloadDestination, progress }) => {
   return new Promise((resolve, reject) => {
-    debug('Downloading from', url)
-    debug('Saving file to', downloadDestination)
+    const proxy = getProxyUrl()
+
+    debug('Downloading package', {
+      url,
+      proxy,
+      downloadDestination,
+    })
 
     let redirectVersion
 
     const req = request({
       url,
+      proxy,
       followRedirect (response) {
         const version = response.headers['x-version']
 
@@ -310,4 +326,5 @@ const start = (opts) => {
 module.exports = {
   start,
   getUrl,
+  getProxyUrl,
 }
diff --git a/cli/package.json b/cli/package.json
index 577cb3ea371b..e38ee0140caf 100644
--- a/cli/package.json
+++ b/cli/package.json
@@ -90,7 +90,7 @@
     "proxyquire": "2.1.0",
     "shelljs": "0.8.3",
     "sinon": "7.2.2",
-    "snap-shot-it": "7.7.1",
+    "snap-shot-it": "7.8.0",
     "spawn-mock": "1.0.0"
   },
   "bin": {
diff --git a/cli/test/lib/tasks/download_spec.js b/cli/test/lib/tasks/download_spec.js
index 2d5e107bcca0..4b237ac7916e 100644
--- a/cli/test/lib/tasks/download_spec.js
+++ b/cli/test/lib/tasks/download_spec.js
@@ -1,5 +1,6 @@
 require('../../spec_helper')
 
+const _ = require('lodash')
 const os = require('os')
 const la = require('lazy-ass')
 const is = require('check-more-types')
@@ -138,7 +139,7 @@ describe('lib/tasks/download', function () {
     })
   })
 
-  describe('verify downloaded file', function () {
+  context('verify downloaded file', function () {
     before(function () {
       this.expectedChecksum = hasha.fromFileSync(examplePath)
       this.expectedFileSize = fs.statSync(examplePath).size
@@ -310,4 +311,30 @@ describe('lib/tasks/download', function () {
       return snapshot('download status errors 1', normalize(ctx.stdout.toString()))
     })
   })
+
+  context('with proxy env vars', () => {
+    beforeEach(function () {
+      this.env = _.clone(process.env)
+    })
+
+    afterEach(function () {
+      process.env = this.env
+    })
+
+    it('prefers https_proxy over http_proxy', () => {
+      process.env.HTTP_PROXY = 'foo'
+      expect(download.getProxyUrl()).to.eq('foo')
+      process.env.https_proxy = 'bar'
+      expect(download.getProxyUrl()).to.eq('bar')
+    })
+
+    it('falls back to npm_config_proxy', () => {
+      process.env.npm_config_proxy = 'foo'
+      expect(download.getProxyUrl()).to.eq('foo')
+      process.env.npm_config_https_proxy = 'bar'
+      expect(download.getProxyUrl()).to.eq('bar')
+      process.env.https_proxy = 'baz'
+      expect(download.getProxyUrl()).to.eq('baz')
+    })
+  })
 })
diff --git a/package.json b/package.json
index dbbc775c7458..cb917ed5596f 100644
--- a/package.json
+++ b/package.json
@@ -145,7 +145,7 @@
     "ramda": "0.24.1",
     "shelljs": "0.8.3",
     "sinon": "7.3.2",
-    "snap-shot-it": "7.7.1",
+    "snap-shot-it": "7.8.0",
     "stop-only": "3.0.1",
     "strip-ansi": "4.0.0",
     "terminal-banner": "1.1.0",
diff --git a/packages/server/lib/util/proxy.ts b/packages/server/lib/util/proxy.ts
index 884d745184a6..fa1463733ec0 100644
--- a/packages/server/lib/util/proxy.ts
+++ b/packages/server/lib/util/proxy.ts
@@ -1,37 +1,75 @@
+import _ from 'lodash'
+import debugModule from 'debug'
 import os from 'os'
 import { getWindowsProxy } from './get-windows-proxy'
 
+const debug = debugModule('cypress:server:util:proxy')
+
+const falsyEnv = (v) => {
+  return v === 'false' || v === '0' || !v
+}
+
 const copyLowercaseEnvToUppercase = (name: string) => {
   // uppercase environment variables are used throughout Cypress and dependencies
   // but users sometimes supply these vars as lowercase
   const lowerEnv = process.env[name.toLowerCase()]
 
   if (lowerEnv) {
+    debug('overriding uppercase env var with lowercase %o', { name })
     process.env[name.toUpperCase()] = lowerEnv
   }
 }
 
 const normalizeEnvironmentProxy = () => {
-  if (process.env.HTTP_PROXY === 'false' || process.env.HTTP_PROXY === '0' || !process.env.HTTP_PROXY) {
+  if (falsyEnv(process.env.HTTP_PROXY)) {
+    debug('HTTP_PROXY is falsy, disabling HTTP_PROXY')
     delete process.env.HTTP_PROXY
   }
 
   if (!process.env.HTTPS_PROXY && process.env.HTTP_PROXY) {
     // request library will use HTTP_PROXY as a fallback for HTTPS urls, but
     // proxy-from-env will not, so let's just force it to fall back like this
+    debug('setting HTTPS_PROXY to HTTP_PROXY since it does not exist')
     process.env.HTTPS_PROXY = process.env.HTTP_PROXY
   }
 
   if (!process.env.hasOwnProperty('NO_PROXY')) {
     // don't proxy localhost, to match Chrome's default behavior and user expectation
+    debug('setting default NO_PROXY of `localhost`')
     process.env.NO_PROXY = 'localhost'
   }
+
+  debug('normalized proxy environment variables %o', _.pick(process.env, [
+    'NO_PROXY', 'HTTP_PROXY', 'HTTPS_PROXY',
+  ]))
+}
+
+const mergeNpmProxyVars = () => {
+  // copy npm's `proxy` and `https-proxy` config if they are set
+  // https://github.com/cypress-io/cypress/pull/4705
+  [
+    ['npm_config_proxy', 'HTTP_PROXY'],
+    ['npm_config_https_proxy', 'HTTPS_PROXY'],
+  ].forEach(([from, to]) => {
+    if (!falsyEnv(process.env[from]) && _.isUndefined(process.env[to])) {
+      debug('using npm\'s %s as %s', from, to)
+      process.env[to] = process.env[from]
+    }
+  })
 }
 
 export const loadSystemProxySettings = () => {
-  ['NO_PROXY', 'HTTP_PROXY', 'HTTPS_PROXY'].forEach(copyLowercaseEnvToUppercase)
+  debug('found proxy environment variables %o', _.pick(process.env, [
+    'NO_PROXY', 'HTTP_PROXY', 'HTTPS_PROXY',
+    'no_proxy', 'http_proxy', 'https_proxy',
+    'npm_config_proxy', 'npm_config_https_proxy',
+  ]))
+
+  ;['NO_PROXY', 'HTTP_PROXY', 'HTTPS_PROXY'].forEach(copyLowercaseEnvToUppercase)
+
+  mergeNpmProxyVars()
 
-  if (typeof process.env.HTTP_PROXY !== 'undefined') {
+  if (!_.isUndefined(process.env.HTTP_PROXY)) {
     normalizeEnvironmentProxy()
 
     return
diff --git a/packages/server/package.json b/packages/server/package.json
index dbef85ba16be..d69d675b7ac8 100644
--- a/packages/server/package.json
+++ b/packages/server/package.json
@@ -182,7 +182,7 @@
     "react": "15.6.2",
     "repl.history": "0.1.4",
     "run-sequence": "1.2.2",
-    "snap-shot-it": "7.7.1",
+    "snap-shot-it": "7.8.0",
     "ssestream": "1.0.1",
     "stream-to-promise": "1.1.1",
     "supertest": "4.0.2",
diff --git a/packages/server/test/unit/args_spec.coffee b/packages/server/test/unit/args_spec.coffee
index 4f258c7bfe7b..9d7f8f78e5ba 100644
--- a/packages/server/test/unit/args_spec.coffee
+++ b/packages/server/test/unit/args_spec.coffee
@@ -394,3 +394,29 @@ describe "lib/util/args", ->
       expect(options.proxySource).to.be.undefined
       expect(options.proxyServer).to.eq process.env.HTTP_PROXY
       expect(options.proxyBypassList).to.eq process.env.NO_PROXY
+
+    it "can use npm_config_proxy", ->
+      process.env.npm_config_proxy = "http://foo-bar.baz:123"
+      expect(process.env.HTTP_PROXY).to.be.undefined
+
+      options = @setup()
+
+      expect(process.env.HTTP_PROXY).to.eq "http://foo-bar.baz:123"
+      expect(process.env.HTTPS_PROXY).to.eq "http://foo-bar.baz:123"
+      expect(process.env.NO_PROXY).to.eq "localhost"
+      expect(options.proxySource).to.be.undefined
+      expect(options.proxyServer).to.eq process.env.HTTP_PROXY
+      expect(options.proxyBypassList).to.eq process.env.NO_PROXY
+
+    it "can override npm_config_proxy with falsy HTTP_PROXY", ->
+      process.env.npm_config_proxy = "http://foo-bar.baz:123"
+      process.env.HTTP_PROXY = ""
+
+      options = @setup()
+
+      expect(process.env.HTTP_PROXY).to.be.undefined
+      expect(process.env.HTTPS_PROXY).to.be.undefined
+      expect(process.env.NO_PROXY).to.eq "localhost"
+      expect(options.proxySource).to.be.undefined
+      expect(options.proxyServer).to.eq process.env.HTTP_PROXY
+      expect(options.proxyBypassList).to.be.undefined