diff --git a/modules/libpref/init/StaticPrefList.yaml b/modules/libpref/init/StaticPrefList.yaml
index 1734cb323cf9..0e4685cf236e 100644
--- a/modules/libpref/init/StaticPrefList.yaml
+++ b/modules/libpref/init/StaticPrefList.yaml
@@ -7791,6 +7791,12 @@
   value: true
   mirror: always
 
+# The maximum allowed length for a URL - 1MB default.
+- name: network.standard-url.max-length
+  type: RelaxedAtomicUint32
+  value: 1048576
+  mirror: always
+
 # Single TRR request timeout, in milliseconds
 - name: network.trr.request_timeout_ms
   type: RelaxedAtomicUint32
diff --git a/modules/libpref/init/all.js b/modules/libpref/init/all.js
index 95483d883e5b..6b9a8100a503 100644
--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -1818,9 +1818,6 @@ pref("network.dns.resolver-thread-extra-idle-time-seconds", 60);
 // Whether to disable TRR when parental control is enabled.
 pref("network.dns.skipTRR-when-parental-control-enabled", true);
 
-// The maximum allowed length for a URL - 1MB default
-pref("network.standard-url.max-length", 1048576);
-
 // Idle timeout for ftp control connections - 5 minute default
 pref("network.ftp.idleConnectionTimeout", 300);
 
diff --git a/netwerk/base/nsStandardURL.cpp b/netwerk/base/nsStandardURL.cpp
index 8b3b408ea500..f70fe5508fca 100644
--- a/netwerk/base/nsStandardURL.cpp
+++ b/netwerk/base/nsStandardURL.cpp
@@ -790,7 +790,7 @@ nsresult nsStandardURL::BuildNormalizedSpec(const char* spec,
 
   // The encoded string could be longer than the original input, so we need
   // to check the final URI isn't longer than the max length.
-  if (approxLen + 1 > (uint32_t)net_GetURLMaxLength()) {
+  if (approxLen + 1 > StaticPrefs::network_standard_url_max_length()) {
     return NS_ERROR_MALFORMED_URI;
   }
 
@@ -949,7 +949,7 @@ nsresult nsStandardURL::BuildNormalizedSpec(const char* spec,
   mSpec.Truncate(strlen(buf));
   NS_ASSERTION(mSpec.Length() <= approxLen,
                "We've overflowed the mSpec buffer!");
-  MOZ_ASSERT(mSpec.Length() <= (uint32_t)net_GetURLMaxLength(),
+  MOZ_ASSERT(mSpec.Length() <= StaticPrefs::network_standard_url_max_length(),
              "The spec should never be this long, we missed a check.");
 
   MOZ_ASSERT(mUsername.mLen != 0 && mPassword.mLen != 0);
@@ -1025,7 +1025,7 @@ int32_t nsStandardURL::ReplaceSegment(uint32_t pos, uint32_t len,
 nsresult nsStandardURL::ParseURL(const char* spec, int32_t specLen) {
   nsresult rv;
 
-  if (specLen > net_GetURLMaxLength()) {
+  if (specLen > (int32_t)StaticPrefs::network_standard_url_max_length()) {
     return NS_ERROR_MALFORMED_URI;
   }
 
@@ -1068,7 +1068,7 @@ nsresult nsStandardURL::ParsePath(const char* spec, uint32_t pathPos,
                                   int32_t pathLen) {
   LOG(("ParsePath: %s pathpos %d len %d\n", spec, pathPos, pathLen));
 
-  if (pathLen > net_GetURLMaxLength()) {
+  if (pathLen > (int32_t)StaticPrefs::network_standard_url_max_length()) {
     return NS_ERROR_MALFORMED_URI;
   }
 
@@ -1202,7 +1202,7 @@ NS_INTERFACE_MAP_END
 // result may contain unescaped UTF-8 characters
 NS_IMETHODIMP
 nsStandardURL::GetSpec(nsACString& result) {
-  MOZ_ASSERT(mSpec.Length() <= (uint32_t)net_GetURLMaxLength(),
+  MOZ_ASSERT(mSpec.Length() <= StaticPrefs::network_standard_url_max_length(),
              "The spec should never be this long, we missed a check.");
   nsresult rv = NS_OK;
   if (StaticPrefs::network_standard_url_punycode_host()) {
@@ -1459,7 +1459,7 @@ nsresult nsStandardURL::SetSpecWithEncoding(const nsACString& input,
   const nsPromiseFlatCString& flat = PromiseFlatCString(input);
   LOG(("nsStandardURL::SetSpec [spec=%s]\n", flat.get()));
 
-  if (input.Length() > (uint32_t)net_GetURLMaxLength()) {
+  if (input.Length() > StaticPrefs::network_standard_url_max_length()) {
     return NS_ERROR_MALFORMED_URI;
   }
 
@@ -1556,7 +1556,7 @@ nsresult nsStandardURL::SetScheme(const nsACString& input) {
   }
 
   if (mSpec.Length() + input.Length() - Scheme().Length() >
-      (uint32_t)net_GetURLMaxLength()) {
+      StaticPrefs::network_standard_url_max_length()) {
     return NS_ERROR_MALFORMED_URI;
   }
 
@@ -1593,7 +1593,7 @@ nsresult nsStandardURL::SetUserPass(const nsACString& input) {
   }
 
   if (mSpec.Length() + input.Length() - Userpass(true).Length() >
-      (uint32_t)net_GetURLMaxLength()) {
+      StaticPrefs::network_standard_url_max_length()) {
     return NS_ERROR_MALFORMED_URI;
   }
 
@@ -1688,7 +1688,7 @@ nsresult nsStandardURL::SetUsername(const nsACString& input) {
   }
 
   if (mSpec.Length() + input.Length() - Username().Length() >
-      (uint32_t)net_GetURLMaxLength()) {
+      StaticPrefs::network_standard_url_max_length()) {
     return NS_ERROR_MALFORMED_URI;
   }
 
@@ -1753,7 +1753,7 @@ nsresult nsStandardURL::SetPassword(const nsACString& input) {
   }
 
   if (mSpec.Length() + input.Length() - Password().Length() >
-      (uint32_t)net_GetURLMaxLength()) {
+      StaticPrefs::network_standard_url_max_length()) {
     return NS_ERROR_MALFORMED_URI;
   }
 
@@ -1923,7 +1923,7 @@ nsresult nsStandardURL::SetHost(const nsACString& input) {
   if (strchr(host, ' ')) return NS_ERROR_MALFORMED_URI;
 
   if (mSpec.Length() + strlen(host) - Host().Length() >
-      (uint32_t)net_GetURLMaxLength()) {
+      StaticPrefs::network_standard_url_max_length()) {
     return NS_ERROR_MALFORMED_URI;
   }
 
@@ -2737,7 +2737,7 @@ nsresult nsStandardURL::SetQueryWithEncoding(const nsACString& input,
   if (mPath.mLen < 0) return SetPathQueryRef(flat);
 
   if (mSpec.Length() + input.Length() - Query().Length() >
-      (uint32_t)net_GetURLMaxLength()) {
+      StaticPrefs::network_standard_url_max_length()) {
     return NS_ERROR_MALFORMED_URI;
   }
 
@@ -2805,7 +2805,7 @@ nsresult nsStandardURL::SetRef(const nsACString& input) {
   if (mPath.mLen < 0) return SetPathQueryRef(flat);
 
   if (mSpec.Length() + input.Length() - Ref().Length() >
-      (uint32_t)net_GetURLMaxLength()) {
+      StaticPrefs::network_standard_url_max_length()) {
     return NS_ERROR_MALFORMED_URI;
   }
 
@@ -2863,7 +2863,7 @@ nsresult nsStandardURL::SetFileNameInternal(const nsACString& input) {
   if (mPath.mLen < 0) return SetPathQueryRef(flat);
 
   if (mSpec.Length() + input.Length() - Filename().Length() >
-      (uint32_t)net_GetURLMaxLength()) {
+      StaticPrefs::network_standard_url_max_length()) {
     return NS_ERROR_MALFORMED_URI;
   }
 
@@ -3054,7 +3054,7 @@ nsresult nsStandardURL::SetFile(nsIFile* file) {
 nsresult nsStandardURL::Init(uint32_t urlType, int32_t defaultPort,
                              const nsACString& spec, const char* charset,
                              nsIURI* baseURI) {
-  if (spec.Length() > (uint32_t)net_GetURLMaxLength() ||
+  if (spec.Length() > StaticPrefs::network_standard_url_max_length() ||
       defaultPort > std::numeric_limits<uint16_t>::max()) {
     return NS_ERROR_MALFORMED_URI;
   }
@@ -3241,7 +3241,7 @@ nsresult nsStandardURL::ReadPrivate(nsIObjectInputStream* stream) {
 
 NS_IMETHODIMP
 nsStandardURL::Write(nsIObjectOutputStream* stream) {
-  MOZ_ASSERT(mSpec.Length() <= (uint32_t)net_GetURLMaxLength(),
+  MOZ_ASSERT(mSpec.Length() <= StaticPrefs::network_standard_url_max_length(),
              "The spec should never be this long, we missed a check.");
   nsresult rv;
 
@@ -3351,7 +3351,7 @@ inline ipc::StandardURLSegment ToIPCSegment(
 }
 
 void nsStandardURL::Serialize(URIParams& aParams) {
-  MOZ_ASSERT(mSpec.Length() <= (uint32_t)net_GetURLMaxLength(),
+  MOZ_ASSERT(mSpec.Length() <= StaticPrefs::network_standard_url_max_length(),
              "The spec should never be this long, we missed a check.");
   StandardURLParams params;
 
@@ -3408,7 +3408,8 @@ bool nsStandardURL::Deserialize(const URIParams& aParams) {
   mPort = params.port();
   mDefaultPort = params.defaultPort();
   mSpec = params.spec();
-  NS_ENSURE_TRUE(mSpec.Length() <= (uint32_t)net_GetURLMaxLength(), false);
+  NS_ENSURE_TRUE(
+      mSpec.Length() <= StaticPrefs::network_standard_url_max_length(), false);
   NS_ENSURE_TRUE(FromIPCSegment(mSpec, params.scheme(), mScheme), false);
   NS_ENSURE_TRUE(FromIPCSegment(mSpec, params.authority(), mAuthority), false);
   NS_ENSURE_TRUE(FromIPCSegment(mSpec, params.username(), mUsername), false);
diff --git a/netwerk/base/nsURLHelper.cpp b/netwerk/base/nsURLHelper.cpp
index b09a8520bed0..7acad59a02a1 100644
--- a/netwerk/base/nsURLHelper.cpp
+++ b/netwerk/base/nsURLHelper.cpp
@@ -19,6 +19,7 @@
 #include "nsNetCID.h"
 #include "mozilla/Preferences.h"
 #include "prnetdb.h"
+#include "mozilla/StaticPrefs_network.h"
 #include "mozilla/Tokenizer.h"
 #include "nsEscape.h"
 #include "mozilla/net/rust_helper.h"
@@ -33,7 +34,6 @@ static bool gInitialized = false;
 static nsIURLParser* gNoAuthURLParser = nullptr;
 static nsIURLParser* gAuthURLParser = nullptr;
 static nsIURLParser* gStdURLParser = nullptr;
-static int32_t gMaxLength = 1048576;  // Default: 1MB
 
 static void InitGlobals() {
   nsCOMPtr<nsIURLParser> parser;
@@ -60,8 +60,6 @@ static void InitGlobals() {
   }
 
   gInitialized = true;
-  Preferences::AddIntVarCache(&gMaxLength, "network.standard-url.max-length",
-                              1048576);
 }
 
 void net_ShutdownURLHelper() {
@@ -73,8 +71,6 @@ void net_ShutdownURLHelper() {
   }
 }
 
-int32_t net_GetURLMaxLength() { return gMaxLength; }
-
 //----------------------------------------------------------------------------
 // nsIURLParser getters
 //----------------------------------------------------------------------------
@@ -139,7 +135,8 @@ nsresult net_ParseFileURL(const nsACString& inURL, nsACString& outDirectory,
                           nsACString& outFileExtension) {
   nsresult rv;
 
-  if (inURL.Length() > (uint32_t)gMaxLength) {
+  if (inURL.Length() >
+      (uint32_t)StaticPrefs::network_standard_url_max_length()) {
     return NS_ERROR_MALFORMED_URI;
   }
 
diff --git a/netwerk/base/nsURLHelper.h b/netwerk/base/nsURLHelper.h
index 3ab9df87a157..74b0fe563393 100644
--- a/netwerk/base/nsURLHelper.h
+++ b/netwerk/base/nsURLHelper.h
@@ -221,10 +221,4 @@ bool net_IsValidIPv4Addr(const nsACString& aAddr);
  */
 bool net_IsValidIPv6Addr(const nsACString& aAddr);
 
-/**
- * Returns the max length of a URL. The default is 1048576 (1 MB).
- * Can be changed by pref "network.standard-url.max-length"
- */
-int32_t net_GetURLMaxLength();
-
 #endif  // !nsURLHelper_h__
diff --git a/netwerk/base/nsURLHelperWin.cpp b/netwerk/base/nsURLHelperWin.cpp
index 5079fc48a55f..b8c9b572c040 100644
--- a/netwerk/base/nsURLHelperWin.cpp
+++ b/netwerk/base/nsURLHelperWin.cpp
@@ -10,8 +10,11 @@
 #include "nsEscape.h"
 #include "nsIFile.h"
 #include <windows.h>
+#include "mozilla/StaticPrefs_network.h"
 #include "mozilla/Utf8.h"
 
+using namespace mozilla;
+
 nsresult net_GetURLSpecFromActualFile(nsIFile* aFile, nsACString& result) {
   nsresult rv;
   nsAutoString path;
@@ -49,7 +52,7 @@ nsresult net_GetURLSpecFromActualFile(nsIFile* aFile, nsACString& result) {
 nsresult net_GetFileFromURLSpec(const nsACString& aURL, nsIFile** result) {
   nsresult rv;
 
-  if (aURL.Length() > (uint32_t)net_GetURLMaxLength()) {
+  if (aURL.Length() > StaticPrefs::network_standard_url_max_length()) {
     return NS_ERROR_MALFORMED_URI;
   }
 
@@ -92,7 +95,7 @@ nsresult net_GetFileFromURLSpec(const nsACString& aURL, nsIFile** result) {
   // remove leading '\'
   if (path.CharAt(0) == '\\') path.Cut(0, 1);
 
-  if (mozilla::IsUtf8(path))
+  if (IsUtf8(path))
     rv = localFile->InitWithPath(NS_ConvertUTF8toUTF16(path));
   // XXX In rare cases, a valid UTF-8 string can be valid as a native
   // encoding (e.g. 0xC5 0x83 is valid both as UTF-8 and Windows-125x).