diff --git a/lighthouse-cli/test/fixtures/seo/seo-tester.html b/lighthouse-cli/test/fixtures/seo/seo-tester.html
index b915c8c8face..cb5b6ef7f676 100644
--- a/lighthouse-cli/test/fixtures/seo/seo-tester.html
+++ b/lighthouse-cli/test/fixtures/seo/seo-tester.html
@@ -22,7 +22,7 @@
 
   <style>
     .small {
-      font-size: 15px;
+      font-size: 11px;
     }
   </style>
 </head>
@@ -36,9 +36,9 @@ <h2>Anchor text</h2>
   <a href='javascript:void(0);'>click this</a>
 
   <h2>Small text</h2>
-  <!-- PASS(font-size): amount of illegible text is below the 75% threshold -->
+  <!-- PASS(font-size): amount of illegible text is below the 60% threshold -->
   <p class='small'> 1 </p>
-  <small>2</small>
+  <h6>2</h6>
   <font size="1">3<b>4</b></font>
   <p style='font-size:10px'>5        </p>
   <script class='small'>
diff --git a/lighthouse-core/audits/seo/font-size.js b/lighthouse-core/audits/seo/font-size.js
index de84486a5172..a22e35db343a 100644
--- a/lighthouse-core/audits/seo/font-size.js
+++ b/lighthouse-core/audits/seo/font-size.js
@@ -9,7 +9,7 @@ const URL = require('../../lib/url-shim');
 const Audit = require('../audit');
 const ViewportAudit = require('../viewport');
 const CSSStyleDeclaration = require('../../lib/web-inspector').CSSStyleDeclaration;
-const MINIMAL_PERCENTAGE_OF_LEGIBLE_TEXT = 75;
+const MINIMAL_PERCENTAGE_OF_LEGIBLE_TEXT = 60;
 
 /**
  * @param {Array<{cssRule: SimplifiedStyleDeclaration, fontSize: number, textLength: number, node: Node}>} fontSizeArtifact
@@ -177,9 +177,9 @@ class FontSize extends Audit {
       name: 'font-size',
       description: 'Document uses legible font sizes',
       failureDescription: 'Document doesn\'t use legible font sizes',
-      helpText: 'Font sizes less than 16px are too small to be legible and require mobile ' +
-      'visitors to “pinch to zoom” in order to read. Strive to have >75% of page text ≥16px. ' +
-      '[Learn more](https://developers.google.com/speed/docs/insights/UseLegibleFontSizes).',
+      helpText: 'Font sizes less than 12px are too small to be legible and require mobile ' +
+      'visitors to “pinch to zoom” in order to read. Strive to have >60% of page text ≥12px. ' +
+      '[Learn more](https://developers.google.com/web/fundamentals/design-and-ux/responsive/#optimize_text_for_reading).',
       requiredArtifacts: ['FontSize', 'URL', 'Viewport'],
     };
   }
@@ -245,7 +245,7 @@ class FontSize extends Audit {
         source: 'Add\'l illegible text',
         selector: null,
         coverage: `${percentageOfUnanalyzedFailingText.toFixed(2)}%`,
-        fontSize: '< 16px',
+        fontSize: '< 12px',
       });
     }
 
@@ -254,7 +254,7 @@ class FontSize extends Audit {
         source: 'Legible text',
         selector: null,
         coverage: `${percentageOfPassingText.toFixed(2)}%`,
-        fontSize: '≥ 16px',
+        fontSize: '≥ 12px',
       });
     }
 
diff --git a/lighthouse-core/gather/gatherers/seo/font-size.js b/lighthouse-core/gather/gatherers/seo/font-size.js
index 16c1b636fc3f..d065809b2f49 100644
--- a/lighthouse-core/gather/gatherers/seo/font-size.js
+++ b/lighthouse-core/gather/gatherers/seo/font-size.js
@@ -18,8 +18,7 @@ const CSSMatchedStyles = require('../../../lib/web-inspector').CSSMatchedStyles;
 const Gatherer = require('../gatherer');
 const FONT_SIZE_PROPERTY_NAME = 'font-size';
 const TEXT_NODE_BLOCK_LIST = new Set(['SCRIPT', 'STYLE', 'NOSCRIPT']);
-// 16px value comes from https://developers.google.com/speed/docs/insights/UseLegibleFontSizes
-const MINIMAL_LEGIBLE_FONT_SIZE_PX = 16;
+const MINIMAL_LEGIBLE_FONT_SIZE_PX = 12;
 // limit number of protocol calls to make sure that gatherer doesn't take more than 1-2s
 const MAX_NODES_VISITED = 500;
 const MAX_NODES_ANALYZED = 50;
diff --git a/lighthouse-core/test/audits/seo/font-size-test.js b/lighthouse-core/test/audits/seo/font-size-test.js
index 00db1ce42073..f9bfe7acc8a7 100644
--- a/lighthouse-core/test/audits/seo/font-size-test.js
+++ b/lighthouse-core/test/audits/seo/font-size-test.js
@@ -27,25 +27,25 @@ describe('SEO: Font size audit', () => {
     assert.ok(auditResult.debugString.includes('missing viewport'));
   });
 
-  it('fails when less than 75% of text is legible', () => {
+  it('fails when less than 60% of text is legible', () => {
     const artifacts = {
       URL,
       Viewport: validViewport,
       FontSize: {
         totalTextLength: 100,
         visitedTextLength: 100,
-        failingTextLength: 33,
-        analyzedFailingTextLength: 33,
+        failingTextLength: 41,
+        analyzedFailingTextLength: 41,
         analyzedFailingNodesData: [
-          {textLength: 11, fontSize: 14, node: {nodeId: 1, localName: 'p', attributes: []}},
-          {textLength: 22, fontSize: 15, node: {nodeId: 2, localName: 'p', attributes: []}},
+          {textLength: 10, fontSize: 10, node: {nodeId: 1, localName: 'p', attributes: []}},
+          {textLength: 31, fontSize: 11, node: {nodeId: 2, localName: 'p', attributes: []}},
         ],
       },
     };
 
     const auditResult = FontSizeAudit.audit(artifacts);
     assert.equal(auditResult.rawValue, false);
-    assert.ok(auditResult.debugString.includes('33%'));
+    assert.ok(auditResult.debugString.includes('41%'));
   });
 
   it('passes when there is no text', () => {
@@ -58,7 +58,7 @@ describe('SEO: Font size audit', () => {
         failingTextLength: 0,
         analyzedFailingTextLength: 0,
         analyzedFailingNodesData: [
-          {textLength: 0, fontSize: 14, node: {nodeId: 1, localName: 'p', attributes: []}},
+          {textLength: 0, fontSize: 11, node: {nodeId: 1, localName: 'p', attributes: []}},
         ],
       },
     };
@@ -67,7 +67,7 @@ describe('SEO: Font size audit', () => {
     assert.equal(auditResult.rawValue, true);
   });
 
-  it('passes when more than 75% of text is legible', () => {
+  it('passes when more than 60% of text is legible', () => {
     const artifacts = {
       URL,
       Viewport: validViewport,
@@ -77,8 +77,8 @@ describe('SEO: Font size audit', () => {
         failingTextLength: 33,
         analyzedFailingTextLength: 33,
         analyzedFailingNodesData: [
-          {textLength: 11, fontSize: 14, node: {nodeId: 1, localName: 'p', attributes: []}},
-          {textLength: 22, fontSize: 15, node: {nodeId: 2, localName: 'p', attributes: []}},
+          {textLength: 11, fontSize: 10, node: {nodeId: 1, localName: 'p', attributes: []}},
+          {textLength: 22, fontSize: 11, node: {nodeId: 2, localName: 'p', attributes: []}},
         ],
       },
     };
@@ -112,9 +112,9 @@ describe('SEO: Font size audit', () => {
         failingTextLength: 7,
         analyzedFailingTextLength: 7,
         analyzedFailingNodesData: [
-          {textLength: 3, fontSize: 15, node: {nodeId: 1}, cssRule: style1},
-          {textLength: 2, fontSize: 14, node: {nodeId: 2}, cssRule: style2},
-          {textLength: 2, fontSize: 14, node: {nodeId: 3}, cssRule: style2},
+          {textLength: 3, fontSize: 11, node: {nodeId: 1}, cssRule: style1},
+          {textLength: 2, fontSize: 10, node: {nodeId: 2}, cssRule: style2},
+          {textLength: 2, fontSize: 10, node: {nodeId: 3}, cssRule: style2},
         ],
       },
     };
@@ -135,7 +135,7 @@ describe('SEO: Font size audit', () => {
         failingTextLength: 50,
         analyzedFailingTextLength: 10,
         analyzedFailingNodesData: [
-          {textLength: 10, fontSize: 14, node: {nodeId: 1, localName: 'p', attributes: []}},
+          {textLength: 10, fontSize: 10, node: {nodeId: 1, localName: 'p', attributes: []}},
         ],
       },
     };
@@ -156,7 +156,7 @@ describe('SEO: Font size audit', () => {
         failingTextLength: 50,
         analyzedFailingTextLength: 50,
         analyzedFailingNodesData: [
-          {textLength: 50, fontSize: 14, node: {nodeId: 1, localName: 'p', attributes: []}},
+          {textLength: 50, fontSize: 10, node: {nodeId: 1, localName: 'p', attributes: []}},
         ],
       },
     };