diff --git a/app/root.css b/app/root.css
index 652e2d58..6908da70 100644
--- a/app/root.css
+++ b/app/root.css
@@ -640,6 +640,16 @@ a:not(:hover, :focus-visible) {
   text-decoration: none;
 }
 
+.contents a[target='_blank'][href^='http']:not(.icon-link, .transparent-link) {
+  padding-right: 12px;
+  background: url('/assets/Icon_External_Link.svg') no-repeat top 3px right 1px / 10px 10px;
+}
+
+sup {
+  /* external link icon above looks best when line-height does not change on lines with footnotes */
+  line-height: 1;
+}
+
 hr {
   border: 1px solid var(--colors-cool-grey-200);
   border-bottom: 0;
diff --git a/public/assets/Icon_External_Link.svg b/public/assets/Icon_External_Link.svg
new file mode 100644
index 00000000..00558966
--- /dev/null
+++ b/public/assets/Icon_External_Link.svg
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- based on https://commons.wikimedia.org/wiki/File:Icon_External_Link.svg -->
+<svg xmlns="http://www.w3.org/2000/svg" width="100" height="100">
+<path fill="transparent" stroke="#146560" stroke-width="10" d="m43,35H5v60h60V57M45,5v10l10,10-30,30 20,20 30-30 10,10h10V5z"/>
+</svg>
\ No newline at end of file