diff --git a/doc/src/sgml/charset.sgml b/doc/src/sgml/charset.sgml
index 4fc22615b73..f7d618c1e15 100644
--- a/doc/src/sgml/charset.sgml
+++ b/doc/src/sgml/charset.sgml
@@ -836,7 +836,7 @@ CREATE COLLATION german (provider = libc, locale = 'de_DE');
 
     See <ulink url="https://www.unicode.org/reports/tr35/tr35-collation.html">Unicode
     Technical Standard #35</ulink>
-    and <ulink url="https://tools.ietf.org/html/bcp47">BCP 47</ulink> for
+    and <ulink url="https://www.rfc-editor.org/info/bcp47">BCP 47</ulink> for
     details.  The list of possible collation types (<literal>co</literal>
     subtag) can be found in
     the <ulink url="https://github.com/unicode-org/cldr/blob/master/common/bcp47/collation.xml">CLDR
diff --git a/doc/src/sgml/client-auth.sgml b/doc/src/sgml/client-auth.sgml
index 246d8825a79..3e7a9efd8cc 100644
--- a/doc/src/sgml/client-auth.sgml
+++ b/doc/src/sgml/client-auth.sgml
@@ -1079,7 +1079,7 @@ omicron         bryanh                  guest1
       <para>
        The method <literal>scram-sha-256</literal> performs SCRAM-SHA-256
        authentication, as described in
-       <ulink url="https://tools.ietf.org/html/rfc7677">RFC 7677</ulink>.  It
+       <ulink url="https://datatracker.ietf.org/doc/html/rfc7677">RFC 7677</ulink>.  It
        is a challenge-response scheme that prevents password sniffing on
        untrusted connections and supports storing passwords on the server in a
        cryptographically hashed form that is thought to be secure.
@@ -1191,7 +1191,7 @@ omicron         bryanh                  guest1
    <para>
     <productname>GSSAPI</productname> is an industry-standard protocol
     for secure authentication defined in
-    <ulink url="https://tools.ietf.org/html/rfc2743">RFC 2743</ulink>.
+    <ulink url="https://datatracker.ietf.org/doc/html/rfc2743">RFC 2743</ulink>.
     <productname>PostgreSQL</productname>
     supports <productname>GSSAPI</productname> for authentication,
     communications encryption, or both.
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index ceb7f647350..330a31c7549 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -4450,7 +4450,7 @@ SELECT format('Testing %3$s, %2$s, %s', 'one', 'two', 'three');
      <listitem>
       <para>
        The <literal>base64</literal> format is that
-       of <ulink url="https://tools.ietf.org/html/rfc2045#section-6.8">RFC
+       of <ulink url="https://datatracker.ietf.org/doc/html/rfc2045#section-6.8">RFC
        2045 Section 6.8</ulink>.  As per the RFC, encoded lines are
        broken at 76 characters.  However instead of the MIME CRLF
        end-of-line marker, only a newline is used for end-of-line.
diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
index 91bd870c29c..87665dbe178 100644
--- a/doc/src/sgml/json.sgml
+++ b/doc/src/sgml/json.sgml
@@ -13,7 +13,7 @@
 
  <para>
   JSON data types are for storing JSON (JavaScript Object Notation)
-  data, as specified in <ulink url="https://tools.ietf.org/html/rfc7159">RFC
+  data, as specified in <ulink url="https://datatracker.ietf.org/doc/html/rfc7159">RFC
   7159</ulink>. Such data can also be stored as <type>text</type>, but
   the JSON data types have the advantage of enforcing that each
   stored value is valid according to the JSON rules.  There are also
diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index 584a6dadb74..1a84241e0ba 100644
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -867,7 +867,7 @@ PQsslKeyPassHook_OpenSSL_type PQgetSSLKeyPassHook_OpenSSL(void);
     connection parameters.  There are two accepted formats for these strings:
     plain keyword/value strings
     and URIs.  URIs generally follow
-    <ulink url="https://tools.ietf.org/html/rfc3986">RFC
+    <ulink url="https://datatracker.ietf.org/doc/html/rfc3986">RFC
     3986</ulink>, except that multi-host connection strings are allowed
     as further described below.
    </para>
@@ -952,7 +952,7 @@ postgresql:///mydb?host=localhost&amp;port=5433
 
    <para>
     The connection <acronym>URI</acronym> needs to be encoded with <ulink
-    url="https://tools.ietf.org/html/rfc3986#section-2.1">percent-encoding</ulink>
+    url="https://datatracker.ietf.org/doc/html/rfc3986#section-2.1">percent-encoding</ulink>
     if it includes symbols with special meaning in any of its parts.  Here is
     an example where the equal sign (<literal>=</literal>) is replaced with
     <literal>%3D</literal> and the space character with
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index c7026462366..97a18a5196f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -2833,7 +2833,7 @@ lo_import 152801
           </indexterm>
           writes column values separated by commas, applying the quoting
           rules described in
-          <ulink url="https://tools.ietf.org/html/rfc4180">RFC 4180</ulink>.
+          <ulink url="https://datatracker.ietf.org/doc/html/rfc4180">RFC 4180</ulink>.
           This output is compatible with the CSV format of the server's
           <command>COPY</command> command.
           A header line with column names is generated unless