diff --git a/CHANGELOG.md b/CHANGELOG.md
index f7da5af2a..db93c73b4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -85,7 +85,8 @@ SPDX-License-Identifier: CC-BY-SA-4.0
 - The dark-mode is also applied to the read-only-view and can be toggled from there.
 - Access tokens for the CLI and 3rd-party-clients can be managed in the user profile.
 - Change editor font to "Fira Code"
-- Note tags can be set as yaml-array in frontmatter
+- Note tags can be set as yaml-array in frontmatter.
+- If only one external login provider is configured, the sign-in button will directly link to it.
 
 ---
 
diff --git a/cypress/integration/autocompletion.spec.ts b/cypress/integration/autocompletion.spec.ts
index 37e79e83a..64b2d869d 100644
--- a/cypress/integration/autocompletion.spec.ts
+++ b/cypress/integration/autocompletion.spec.ts
@@ -6,6 +6,7 @@
 
 describe('Autocompletion', () => {
   beforeEach(() => {
+    cy.loadConfig()
     cy.visitTestEditor()
     cy.get('.CodeMirror')
       .click()
diff --git a/cypress/integration/banner.spec.ts b/cypress/integration/banner.spec.ts
index 6dcbcd34f..bbb136c66 100644
--- a/cypress/integration/banner.spec.ts
+++ b/cypress/integration/banner.spec.ts
@@ -8,6 +8,7 @@ import { banner } from '../support/config'
 
 describe('Banner', () => {
   beforeEach(() => {
+    cy.loadConfig()
     cy.visit('/')
     expect(localStorage.getItem('bannerTimeStamp')).to.be.null
   })
diff --git a/cypress/integration/diagrams.spec.ts b/cypress/integration/diagrams.spec.ts
index 186810da3..87ad5fb02 100644
--- a/cypress/integration/diagrams.spec.ts
+++ b/cypress/integration/diagrams.spec.ts
@@ -6,6 +6,7 @@
 
 describe('Diagram codeblock ', () => {
   beforeEach(() => {
+    cy.loadConfig()
     cy.visitTestEditor()
   })
 
diff --git a/cypress/integration/documentTitle.spec.ts b/cypress/integration/documentTitle.spec.ts
index 8d7745708..807332426 100644
--- a/cypress/integration/documentTitle.spec.ts
+++ b/cypress/integration/documentTitle.spec.ts
@@ -9,6 +9,7 @@ import { branding } from '../support/config'
 const title = 'This is a test title'
 describe('Document Title', () => {
   beforeEach(() => {
+    cy.loadConfig()
     cy.visitTestEditor()
     cy.get('.btn.active.btn-outline-secondary > i.fa-columns')
       .should('exist')
diff --git a/cypress/integration/editorMode.spec.ts b/cypress/integration/editorMode.spec.ts
index 906b2d583..ae5e5c4a6 100644
--- a/cypress/integration/editorMode.spec.ts
+++ b/cypress/integration/editorMode.spec.ts
@@ -5,6 +5,10 @@
  */
 
 describe('Editor mode from URL parameter is used', () => {
+  beforeEach(() => {
+    cy.loadConfig()
+  })
+
   it('mode view', () => {
     cy.visitTestEditor('view')
     cy.get('.splitter.left')
diff --git a/cypress/integration/export.spec.ts b/cypress/integration/export.spec.ts
index b76a44160..b93a57f9f 100644
--- a/cypress/integration/export.spec.ts
+++ b/cypress/integration/export.spec.ts
@@ -9,6 +9,7 @@ describe('Export', () => {
   const testContent = `---\ntitle: ${ testTitle }\n---\nThis is some test content`
 
   beforeEach(() => {
+    cy.loadConfig()
     cy.visitTestEditor()
     cy.codemirrorFill(testContent)
   })
diff --git a/cypress/integration/fileUpload.spec.ts b/cypress/integration/fileUpload.spec.ts
index 7cc136988..f8ea47132 100644
--- a/cypress/integration/fileUpload.spec.ts
+++ b/cypress/integration/fileUpload.spec.ts
@@ -8,6 +8,7 @@ const imageUrl = 'http://example.com/non-existing.png'
 
 describe('File upload', () => {
   beforeEach(() => {
+    cy.loadConfig()
     cy.visitTestEditor()
   })
 
diff --git a/cypress/integration/helpDialog.spec.ts b/cypress/integration/helpDialog.spec.ts
index 1c9c73548..355d9b030 100644
--- a/cypress/integration/helpDialog.spec.ts
+++ b/cypress/integration/helpDialog.spec.ts
@@ -6,6 +6,7 @@
 
 describe('Help Dialog', () => {
   beforeEach(() => {
+    cy.loadConfig()
     cy.visitTestEditor()
   })
 
diff --git a/cypress/integration/highlightedCodeBlock.spec.ts b/cypress/integration/highlightedCodeBlock.spec.ts
index ecc3463c2..5ea0d6af1 100644
--- a/cypress/integration/highlightedCodeBlock.spec.ts
+++ b/cypress/integration/highlightedCodeBlock.spec.ts
@@ -12,6 +12,7 @@ const findHljsCodeBlock = () => {
 
 describe('Code', () => {
   beforeEach(() => {
+    cy.loadConfig()
     cy.visitTestEditor()
   })
 
diff --git a/cypress/integration/history.spec.ts b/cypress/integration/history.spec.ts
index 5ae951eb8..8711c3dee 100644
--- a/cypress/integration/history.spec.ts
+++ b/cypress/integration/history.spec.ts
@@ -6,6 +6,7 @@
 
 describe('History', () => {
   beforeEach(() => {
+    cy.loadConfig()
     cy.visit('/history')
   })
 
diff --git a/cypress/integration/import.spec.ts b/cypress/integration/import.spec.ts
index df75f90de..1c0812337 100644
--- a/cypress/integration/import.spec.ts
+++ b/cypress/integration/import.spec.ts
@@ -6,6 +6,7 @@
 
 describe('Import markdown file', () => {
   beforeEach(() => {
+    cy.loadConfig()
     cy.visitTestEditor()
   })
 
diff --git a/cypress/integration/intro.spec.ts b/cypress/integration/intro.spec.ts
index a3517d97e..ef153b942 100644
--- a/cypress/integration/intro.spec.ts
+++ b/cypress/integration/intro.spec.ts
@@ -7,6 +7,7 @@
 /* eslint-disable @typescript-eslint/no-unsafe-call */
 describe('Intro page', () => {
   beforeEach(() => {
+    cy.loadConfig()
     cy.intercept('/intro.md', 'test content')
     cy.visit('/')
   })
diff --git a/cypress/integration/language.spec.ts b/cypress/integration/language.spec.ts
index 50c398ce8..1aa0b8964 100644
--- a/cypress/integration/language.spec.ts
+++ b/cypress/integration/language.spec.ts
@@ -8,6 +8,7 @@ import { languages } from '../fixtures/languages'
 
 describe('Languages', () => {
   beforeEach(() => {
+    cy.loadConfig()
     cy.visit('/')
   })
 
diff --git a/cypress/integration/link.spec.ts b/cypress/integration/link.spec.ts
index da5c4552b..22df80efd 100644
--- a/cypress/integration/link.spec.ts
+++ b/cypress/integration/link.spec.ts
@@ -8,6 +8,7 @@ import '../support/index'
 
 describe('Links Intro', () => {
   beforeEach(() => {
+    cy.loadConfig()
     cy.visit('/')
   })
 
@@ -53,13 +54,6 @@ describe('Links Intro', () => {
       cy.url()
         .should('include', '/new')
     })
-
-    it('Sign In', () => {
-      cy.get('.btn-success.btn-sm')
-        .click()
-      cy.url()
-        .should('include', '/login')
-    })
   })
 
   describe('Menu Buttons logged in', () => {
@@ -83,7 +77,7 @@ describe('Links Intro', () => {
           .should('include', '/features')
       })
 
-      it('Features', () => {
+      it('Profile', () => {
         cy.get('a.dropdown-item > i.fa-user')
           .click()
         cy.url()
diff --git a/cypress/integration/linkEmbedder.spec.ts b/cypress/integration/linkEmbedder.spec.ts
index 6b988bd2e..d3fb92e00 100644
--- a/cypress/integration/linkEmbedder.spec.ts
+++ b/cypress/integration/linkEmbedder.spec.ts
@@ -6,6 +6,7 @@
 
 describe('Link gets replaced with embedding: ', () => {
   beforeEach(() => {
+    cy.loadConfig()
     cy.visitTestEditor()
   })
 
diff --git a/cypress/integration/maxLength.spec.ts b/cypress/integration/maxLength.spec.ts
index 1aca4b986..8fee6cb7f 100644
--- a/cypress/integration/maxLength.spec.ts
+++ b/cypress/integration/maxLength.spec.ts
@@ -10,6 +10,7 @@ describe('The status bar text length info', () => {
   const tooMuchTestContent = `${ dangerTestContent }a`
 
   beforeEach(() => {
+    cy.loadConfig()
     cy.visitTestEditor()
   })
 
diff --git a/cypress/integration/profile.spec.ts b/cypress/integration/profile.spec.ts
index e5183db5f..ecbc9e0cd 100644
--- a/cypress/integration/profile.spec.ts
+++ b/cypress/integration/profile.spec.ts
@@ -6,6 +6,7 @@
 
 describe('profile page', () => {
   beforeEach(() => {
+    cy.loadConfig()
     cy.intercept({
       url: '/api/v2/tokens',
       method: 'GET'
diff --git a/cypress/integration/quote-extra.spec.ts b/cypress/integration/quote-extra.spec.ts
index 29b0d25ae..a5e0aa19f 100644
--- a/cypress/integration/quote-extra.spec.ts
+++ b/cypress/integration/quote-extra.spec.ts
@@ -6,6 +6,7 @@
 
 describe('Quote extra tags', function () {
   beforeEach(() => {
+    cy.loadConfig()
     cy.visitTestEditor()
   })
 
diff --git a/cypress/integration/shortcodes.spec.ts b/cypress/integration/shortcodes.spec.ts
index 719c3ab9b..a1bf85a6c 100644
--- a/cypress/integration/shortcodes.spec.ts
+++ b/cypress/integration/shortcodes.spec.ts
@@ -6,6 +6,7 @@
 
 describe('Short code gets replaced or rendered: ', () => {
   beforeEach(() => {
+    cy.loadConfig()
     cy.visitTestEditor()
   })
 
diff --git a/cypress/integration/signInButton.spec.ts b/cypress/integration/signInButton.spec.ts
new file mode 100644
index 000000000..f3e7030d5
--- /dev/null
+++ b/cypress/integration/signInButton.spec.ts
@@ -0,0 +1,114 @@
+/*
+ * SPDX-FileCopyrightText: 2021 The HedgeDoc developers (see AUTHORS file)
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+const authProvidersDisabled = {
+  facebook: false,
+  github: false,
+  twitter: false,
+  gitlab: false,
+  dropbox: false,
+  ldap: false,
+  google: false,
+  saml: false,
+  oauth2: false,
+  internal: false,
+  openid: false
+}
+
+const initLoggedOutTestWithCustomAuthProviders = (cy: Cypress.cy, enabledProviders: Partial<typeof authProvidersDisabled>) => {
+  cy.loadConfig({
+    authProviders: {
+      ...authProvidersDisabled,
+      ...enabledProviders
+    }
+  })
+  cy.visit('/')
+  cy.logout()
+}
+
+describe('When logged-in, ', () => {
+  it('sign-in button is hidden', () => {
+    cy.loadConfig()
+    cy.visit('/')
+    cy.get('[data-cy=sign-in-button]')
+      .should('not.exist')
+  })
+})
+
+describe('When logged-out ', () => {
+  describe('and no auth-provider is enabled, ', () => {
+    it('sign-in button is hidden', () => {
+      initLoggedOutTestWithCustomAuthProviders(cy, {})
+      cy.get('[data-cy=sign-in-button]')
+        .should('not.exist')
+    })
+  })
+
+  describe('and an interactive auth-provider is enabled, ', () => {
+    it('sign-in button points to login route: internal', () => {
+      initLoggedOutTestWithCustomAuthProviders(cy, {
+        internal: true
+      })
+      cy.get('[data-cy=sign-in-button]')
+        .should('be.visible')
+        .should('have.attr', 'href', '/login')
+    })
+
+    it('sign-in button points to login route: ldap', () => {
+      initLoggedOutTestWithCustomAuthProviders(cy, {
+        ldap: true
+      })
+      cy.get('[data-cy=sign-in-button]')
+        .should('be.visible')
+        .should('have.attr', 'href', '/login')
+    })
+
+    it('sign-in button points to login route: openid', () => {
+      initLoggedOutTestWithCustomAuthProviders(cy, {
+        openid: true
+      })
+      cy.get('[data-cy=sign-in-button]')
+        .should('be.visible')
+        .should('have.attr', 'href', '/login')
+    })
+  })
+
+  describe('and only one one-click auth-provider is enabled, ', () => {
+    it('sign-in button points to auth-provider', () => {
+      initLoggedOutTestWithCustomAuthProviders(cy, {
+        saml: true
+      })
+      cy.get('[data-cy=sign-in-button]')
+        .should('be.visible')
+        // The absolute URL is used because it is defined as API base URL absolute.
+        .should('have.attr', 'href', 'http://127.0.0.1:3001/api/v2/auth/saml')
+    })
+  })
+
+  describe('and multiple one-click auth-providers are enabled, ', () => {
+    it('sign-in button points to login route', () => {
+      initLoggedOutTestWithCustomAuthProviders(cy, {
+        saml: true,
+        github: true
+      })
+      cy.get('[data-cy=sign-in-button]')
+        .should('be.visible')
+        .should('have.attr', 'href', '/login')
+    })
+  })
+
+  describe('and one-click- as well as interactive auth-providers are enabled, ', () => {
+    it('sign-in button points to login route', () => {
+      initLoggedOutTestWithCustomAuthProviders(cy, {
+        saml: true,
+        internal: true
+      })
+      cy.get('[data-cy=sign-in-button]')
+        .should('be.visible')
+        .should('have.attr', 'href', '/login')
+    })
+  })
+})
diff --git a/cypress/integration/toolbar.spec.ts b/cypress/integration/toolbar.spec.ts
index 3053c9c0f..d2ea5417d 100644
--- a/cypress/integration/toolbar.spec.ts
+++ b/cypress/integration/toolbar.spec.ts
@@ -9,6 +9,7 @@ describe('Toolbar Buttons', () => {
   const testLink = 'http://hedgedoc.org'
 
   beforeEach(() => {
+    cy.loadConfig()
     cy.visitTestEditor()
 
     cy.get('.CodeMirror')
diff --git a/cypress/integration/yamlArrayDeprecationMessage.spec.ts b/cypress/integration/yamlArrayDeprecationMessage.spec.ts
index 681a711ef..7e1a4c303 100644
--- a/cypress/integration/yamlArrayDeprecationMessage.spec.ts
+++ b/cypress/integration/yamlArrayDeprecationMessage.spec.ts
@@ -6,6 +6,7 @@
 
 describe('YAML Array for deprecated syntax of document tags in frontmatter', () => {
   beforeEach(() => {
+    cy.loadConfig()
     cy.visitTestEditor()
   })
 
diff --git a/cypress/support/config.ts b/cypress/support/config.ts
index bac8e4f95..a8fd9f391 100644
--- a/cypress/support/config.ts
+++ b/cypress/support/config.ts
@@ -4,6 +4,12 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
+declare namespace Cypress {
+  interface Chainable {
+    loadConfig(): Chainable<Window>
+  }
+}
+
 export const banner = {
   text: 'This is the mock banner call',
   timestamp: '2020-05-22T20:46:08.962Z'
@@ -14,47 +20,54 @@ export const branding = {
   logo: '/img/acme.png'
 }
 
-beforeEach(() => {
-  cy.intercept('/api/v2/config', {
+export const authProviders = {
+  facebook: true,
+  github: true,
+  twitter: true,
+  gitlab: true,
+  dropbox: true,
+  ldap: true,
+  google: true,
+  saml: true,
+  oauth2: true,
+  internal: true,
+  openid: true
+}
+
+export const config = {
+  allowAnonymous: true,
+  authProviders: authProviders,
+  branding: branding,
+  banner: banner,
+  customAuthNames: {
+    ldap: 'FooBar',
+    oauth2: 'Olaf2',
+    saml: 'aufSAMLn.de'
+  },
+  maxDocumentLength: 200,
+  specialLinks: {
+    privacy: 'https://example.com/privacy',
+    termsOfUse: 'https://example.com/termsOfUse',
+    imprint: 'https://example.com/imprint'
+  },
+  plantumlServer: 'http://mock-plantuml.local',
+  version: {
+    version: 'mock',
+    sourceCodeUrl: 'https://www.youtube.com/watch?v=dQw4w9WgXcQ',
+    issueTrackerUrl: 'https://www.youtube.com/watch?v=dQw4w9WgXcQ'
+  },
+  'iframeCommunication': {
+    'editorOrigin': 'http://127.0.0.1:3001',
+    'rendererOrigin': 'http://127.0.0.1:3001'
+  }
+}
+
+Cypress.Commands.add('loadConfig', (additionalConfig?: Partial<typeof config>) => {
+  return cy.intercept('/api/v2/config', {
     statusCode: 200,
     body: {
-      allowAnonymous: true,
-      authProviders: {
-        facebook: true,
-        github: true,
-        twitter: true,
-        gitlab: true,
-        dropbox: true,
-        ldap: true,
-        google: true,
-        saml: true,
-        oauth2: true,
-        email: true,
-        openid: true
-      },
-      branding: branding,
-      banner: banner,
-      customAuthNames: {
-        ldap: 'FooBar',
-        oauth2: 'Olaf2',
-        saml: 'aufSAMLn.de'
-      },
-      maxDocumentLength: 200,
-      specialLinks: {
-        privacy: 'https://example.com/privacy',
-        termsOfUse: 'https://example.com/termsOfUse',
-        imprint: 'https://example.com/imprint'
-      },
-      plantumlServer: 'http://mock-plantuml.local',
-      version: {
-        version: 'mock',
-        sourceCodeUrl: 'https://www.youtube.com/watch?v=dQw4w9WgXcQ',
-        issueTrackerUrl: 'https://www.youtube.com/watch?v=dQw4w9WgXcQ'
-      },
-      'iframeCommunication': {
-        'editorOrigin': 'http://127.0.0.1:3001',
-        'rendererOrigin': 'http://127.0.0.1:3001'
-      }
+      ...config,
+      ...additionalConfig
     }
   })
 })
diff --git a/src/api/auth/index.ts b/src/api/auth/index.ts
index 0b2994bbf..7228ae302 100644
--- a/src/api/auth/index.ts
+++ b/src/api/auth/index.ts
@@ -7,6 +7,8 @@
 import { RegisterError } from '../../components/register-page/register-page'
 import { defaultFetchConfig, expectResponseCode, getApiUrl } from '../utils'
 
+export const INTERACTIVE_LOGIN_METHODS = ['internal', 'ldap', 'openid']
+
 export const doInternalLogin = async (username: string, password: string): Promise<void> => {
   const response = await fetch(getApiUrl() + '/auth/internal', {
     ...defaultFetchConfig,
diff --git a/src/components/landing-layout/navigation/sign-in-button.tsx b/src/components/landing-layout/navigation/sign-in-button.tsx
index 743ea7180..3d6909f5f 100644
--- a/src/components/landing-layout/navigation/sign-in-button.tsx
+++ b/src/components/landing-layout/navigation/sign-in-button.tsx
@@ -4,7 +4,8 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
-import React from 'react'
+import equal from 'fast-deep-equal'
+import React, { useMemo } from 'react'
 import { Button } from 'react-bootstrap'
 import { ButtonProps } from 'react-bootstrap/Button'
 import { Trans, useTranslation } from 'react-i18next'
@@ -12,16 +13,31 @@ import { useSelector } from 'react-redux'
 import { LinkContainer } from 'react-router-bootstrap'
 import { ApplicationState } from '../../../redux'
 import { ShowIf } from '../../common/show-if/show-if'
+import { getApiUrl } from '../../../api/utils'
+import { INTERACTIVE_LOGIN_METHODS } from '../../../api/auth'
 
 export type SignInButtonProps = Omit<ButtonProps, 'href'>
 
 export const SignInButton: React.FC<SignInButtonProps> = ({ variant, ...props }) => {
   const { t } = useTranslation()
-  const anyAuthProviderActive = useSelector((state: ApplicationState) => Object.values(state.config.authProviders)
-                                                                               .includes(true))
+  const authProviders = useSelector((state: ApplicationState) => state.config.authProviders, equal)
+  const authEnabled = useMemo(() => Object.values(authProviders).includes(true), [authProviders])
+
+  const loginLink = useMemo(() => {
+    const activeProviders = Object.entries(authProviders)
+                                  .filter((entry: [string, boolean]) => entry[1])
+                                  .map(entry => entry[0])
+    const activeOneClickProviders = activeProviders.filter(entry => !INTERACTIVE_LOGIN_METHODS.includes(entry))
+
+    if (activeProviders.length === 1 && activeOneClickProviders.length === 1) {
+      return `${ getApiUrl() }/auth/${ activeOneClickProviders[0] }`
+    }
+    return '/login'
+  }, [authProviders])
+
   return (
-    <ShowIf condition={ anyAuthProviderActive }>
-      <LinkContainer to="/login" title={ t('login.signIn') }>
+    <ShowIf condition={ authEnabled }>
+      <LinkContainer to={ loginLink } title={ t('login.signIn') }>
         <Button
           data-cy={ 'sign-in-button' }
           variant={ variant || 'success' }