diff --git a/build.zig b/build.zig
index 21b323df5697..e7e3f17a8242 100644
--- a/build.zig
+++ b/build.zig
@@ -239,7 +239,7 @@ pub fn build(b: *std.Build) !void {
             },
             2 => {
                 // Untagged development build (e.g. 0.10.0-dev.2025+ecf0050a9).
-                var it = mem.split(u8, git_describe, "-");
+                var it = mem.splitScalar(u8, git_describe, '-');
                 const tagged_ancestor = it.first();
                 const commit_height = it.next().?;
                 const commit_id = it.next().?;
@@ -859,14 +859,14 @@ fn parseConfigH(b: *std.Build, config_h_text: []const u8) ?CMakeConfig {
     while (lines_it.next()) |line| {
         inline for (mappings) |mapping| {
             if (mem.startsWith(u8, line, mapping.prefix)) {
-                var it = mem.split(u8, line, "\"");
+                var it = mem.splitScalar(u8, line, '"');
                 _ = it.first(); // skip the stuff before the quote
                 const quoted = it.next().?; // the stuff inside the quote
                 @field(ctx, mapping.field) = toNativePathSep(b, quoted);
             }
         }
         if (mem.startsWith(u8, line, "#define ZIG_LLVM_LINK_MODE ")) {
-            var it = mem.split(u8, line, "\"");
+            var it = mem.splitScalar(u8, line, '"');
             _ = it.next().?; // skip the stuff before the quote
             const quoted = it.next().?; // the stuff inside the quote
             ctx.llvm_linkage = if (mem.eql(u8, quoted, "shared")) .dynamic else .static;
diff --git a/doc/docgen.zig b/doc/docgen.zig
index 07636fd1527a..82f2d9b1996a 100644
--- a/doc/docgen.zig
+++ b/doc/docgen.zig
@@ -1223,7 +1223,7 @@ fn printShell(out: anytype, shell_content: []const u8, escape: bool) !void {
     const trimmed_shell_content = mem.trim(u8, shell_content, " \n");
     try out.writeAll("<figure><figcaption class=\"shell-cap\">Shell</figcaption><pre><samp>");
     var cmd_cont: bool = false;
-    var iter = std.mem.split(u8, trimmed_shell_content, "\n");
+    var iter = std.mem.splitScalar(u8, trimmed_shell_content, '\n');
     while (iter.next()) |orig_line| {
         const line = mem.trimRight(u8, orig_line, " ");
         if (!cmd_cont and line.len > 1 and mem.eql(u8, line[0..2], "$ ") and line[line.len - 1] != '\\') {
diff --git a/lib/std/Build/Step/Compile.zig b/lib/std/Build/Step/Compile.zig
index 6a05adc1a6d0..3355d7ccc5ee 100644
--- a/lib/std/Build/Step/Compile.zig
+++ b/lib/std/Build/Step/Compile.zig
@@ -2140,7 +2140,7 @@ fn checkCompileErrors(self: *Compile) !void {
     // Render the expected lines into a string that we can compare verbatim.
     var expected_generated = std.ArrayList(u8).init(arena);
 
-    var actual_line_it = mem.split(u8, actual_stderr, "\n");
+    var actual_line_it = mem.splitScalar(u8, actual_stderr, '\n');
     for (self.expect_errors) |expect_line| {
         const actual_line = actual_line_it.next() orelse {
             try expected_generated.appendSlice(expect_line);
diff --git a/lib/std/Build/Step/ConfigHeader.zig b/lib/std/Build/Step/ConfigHeader.zig
index e19f7f5fd9da..b010cab867f9 100644
--- a/lib/std/Build/Step/ConfigHeader.zig
+++ b/lib/std/Build/Step/ConfigHeader.zig
@@ -250,7 +250,7 @@ fn render_autoconf(
 
     var any_errors = false;
     var line_index: u32 = 0;
-    var line_it = std.mem.split(u8, contents, "\n");
+    var line_it = std.mem.splitScalar(u8, contents, '\n');
     while (line_it.next()) |line| : (line_index += 1) {
         if (!std.mem.startsWith(u8, line, "#")) {
             try output.appendSlice(line);
@@ -297,7 +297,7 @@ fn render_cmake(
 
     var any_errors = false;
     var line_index: u32 = 0;
-    var line_it = std.mem.split(u8, contents, "\n");
+    var line_it = std.mem.splitScalar(u8, contents, '\n');
     while (line_it.next()) |line| : (line_index += 1) {
         if (!std.mem.startsWith(u8, line, "#")) {
             try output.appendSlice(line);
diff --git a/lib/std/SemanticVersion.zig b/lib/std/SemanticVersion.zig
index 26f6f581c83b..4d505b4e30f1 100644
--- a/lib/std/SemanticVersion.zig
+++ b/lib/std/SemanticVersion.zig
@@ -42,8 +42,8 @@ pub fn order(lhs: Version, rhs: Version) std.math.Order {
     if (lhs.pre == null and rhs.pre != null) return .gt;
 
     // Iterate over pre-release identifiers until a difference is found.
-    var lhs_pre_it = std.mem.split(u8, lhs.pre.?, ".");
-    var rhs_pre_it = std.mem.split(u8, rhs.pre.?, ".");
+    var lhs_pre_it = std.mem.splitScalar(u8, lhs.pre.?, '.');
+    var rhs_pre_it = std.mem.splitScalar(u8, rhs.pre.?, '.');
     while (true) {
         const next_lid = lhs_pre_it.next();
         const next_rid = rhs_pre_it.next();
@@ -86,7 +86,7 @@ pub fn parse(text: []const u8) !Version {
     // Parse the required major, minor, and patch numbers.
     const extra_index = std.mem.indexOfAny(u8, text, "-+");
     const required = text[0..(extra_index orelse text.len)];
-    var it = std.mem.split(u8, required, ".");
+    var it = std.mem.splitScalar(u8, required, '.');
     var ver = Version{
         .major = try parseNum(it.first()),
         .minor = try parseNum(it.next() orelse return error.InvalidVersion),
@@ -108,7 +108,7 @@ pub fn parse(text: []const u8) !Version {
     // Check validity of optional pre-release identifiers.
     // See: https://semver.org/#spec-item-9
     if (ver.pre) |pre| {
-        it = std.mem.split(u8, pre, ".");
+        it = std.mem.splitScalar(u8, pre, '.');
         while (it.next()) |id| {
             // Identifiers MUST NOT be empty.
             if (id.len == 0) return error.InvalidVersion;
@@ -127,7 +127,7 @@ pub fn parse(text: []const u8) !Version {
     // Check validity of optional build metadata identifiers.
     // See: https://semver.org/#spec-item-10
     if (ver.build) |build| {
-        it = std.mem.split(u8, build, ".");
+        it = std.mem.splitScalar(u8, build, '.');
         while (it.next()) |id| {
             // Identifiers MUST NOT be empty.
             if (id.len == 0) return error.InvalidVersion;
diff --git a/lib/std/builtin.zig b/lib/std/builtin.zig
index ea513ae87e9f..89f1028aefd0 100644
--- a/lib/std/builtin.zig
+++ b/lib/std/builtin.zig
@@ -531,7 +531,7 @@ pub const Version = struct {
         // found no digits or '.' before unexpected character
         if (end == 0) return error.InvalidVersion;
 
-        var it = std.mem.split(u8, text[0..end], ".");
+        var it = std.mem.splitScalar(u8, text[0..end], '.');
         // substring is not empty, first call will succeed
         const major = it.first();
         if (major.len == 0) return error.InvalidVersion;
diff --git a/lib/std/crypto/Certificate.zig b/lib/std/crypto/Certificate.zig
index 113d169cbcfe..3da4269ba2b2 100644
--- a/lib/std/crypto/Certificate.zig
+++ b/lib/std/crypto/Certificate.zig
@@ -337,8 +337,8 @@ pub const Parsed = struct {
             return true; // exact match
         }
 
-        var it_host = std.mem.split(u8, host_name, ".");
-        var it_dns = std.mem.split(u8, dns_name, ".");
+        var it_host = std.mem.splitScalar(u8, host_name, '.');
+        var it_dns = std.mem.splitScalar(u8, dns_name, '.');
 
         const len_match = while (true) {
             const host = it_host.next();
diff --git a/lib/std/crypto/phc_encoding.zig b/lib/std/crypto/phc_encoding.zig
index cc0f10e395c4..1eeee39a5a10 100644
--- a/lib/std/crypto/phc_encoding.zig
+++ b/lib/std/crypto/phc_encoding.zig
@@ -7,9 +7,12 @@ const mem = std.mem;
 const meta = std.meta;
 
 const fields_delimiter = "$";
+const fields_delimiter_scalar = '$';
 const version_param_name = "v";
 const params_delimiter = ",";
+const params_delimiter_scalar = ',';
 const kv_delimiter = "=";
+const kv_delimiter_scalar = '=';
 
 pub const Error = std.crypto.errors.EncodingError || error{NoSpaceLeft};
 
@@ -73,7 +76,7 @@ pub fn BinValue(comptime max_len: usize) type {
 /// Other fields will also be deserialized from the function parameters section.
 pub fn deserialize(comptime HashResult: type, str: []const u8) Error!HashResult {
     var out = mem.zeroes(HashResult);
-    var it = mem.split(u8, str, fields_delimiter);
+    var it = mem.splitScalar(u8, str, fields_delimiter_scalar);
     var set_fields: usize = 0;
 
     while (true) {
@@ -104,7 +107,7 @@ pub fn deserialize(comptime HashResult: type, str: []const u8) Error!HashResult
 
         // Read optional parameters
         var has_params = false;
-        var it_params = mem.split(u8, field, params_delimiter);
+        var it_params = mem.splitScalar(u8, field, params_delimiter_scalar);
         while (it_params.next()) |params| {
             const param = kvSplit(params) catch break;
             var found = false;
@@ -252,7 +255,7 @@ fn serializeTo(params: anytype, out: anytype) !void {
 
 // Split a `key=value` string into `key` and `value`
 fn kvSplit(str: []const u8) !struct { key: []const u8, value: []const u8 } {
-    var it = mem.split(u8, str, kv_delimiter);
+    var it = mem.splitScalar(u8, str, kv_delimiter_scalar);
     const key = it.first();
     const value = it.next() orelse return Error.InvalidEncoding;
     const ret = .{ .key = key, .value = value };
diff --git a/lib/std/crypto/scrypt.zig b/lib/std/crypto/scrypt.zig
index 077de3b5108c..b8e8ef55e2de 100644
--- a/lib/std/crypto/scrypt.zig
+++ b/lib/std/crypto/scrypt.zig
@@ -287,7 +287,7 @@ const crypt_format = struct {
         out.r = try Codec.intDecode(u30, str[4..9]);
         out.p = try Codec.intDecode(u30, str[9..14]);
 
-        var it = mem.split(u8, str[14..], "$");
+        var it = mem.splitScalar(u8, str[14..], '$');
 
         const salt = it.first();
         if (@hasField(T, "salt")) out.salt = salt;
diff --git a/lib/std/http/Client.zig b/lib/std/http/Client.zig
index 857cb5b0e58d..9fb60c3614bb 100644
--- a/lib/std/http/Client.zig
+++ b/lib/std/http/Client.zig
@@ -406,7 +406,7 @@ pub const Response = struct {
             } else if (std.ascii.eqlIgnoreCase(header_name, "transfer-encoding")) {
                 // Transfer-Encoding: second, first
                 // Transfer-Encoding: deflate, chunked
-                var iter = mem.splitBackwards(u8, header_value, ",");
+                var iter = mem.splitBackwardsScalar(u8, header_value, ',');
 
                 if (iter.next()) |first| {
                     const trimmed = mem.trim(u8, first, " ");
diff --git a/lib/std/http/Server.zig b/lib/std/http/Server.zig
index 36bd8b385720..8dd35b8bb5ec 100644
--- a/lib/std/http/Server.zig
+++ b/lib/std/http/Server.zig
@@ -257,7 +257,7 @@ pub const Request = struct {
             } else if (std.ascii.eqlIgnoreCase(header_name, "transfer-encoding")) {
                 // Transfer-Encoding: second, first
                 // Transfer-Encoding: deflate, chunked
-                var iter = mem.splitBackwards(u8, header_value, ",");
+                var iter = mem.splitBackwardsScalar(u8, header_value, ',');
 
                 if (iter.next()) |first| {
                     const trimmed = mem.trim(u8, first, " ");
diff --git a/lib/std/net.zig b/lib/std/net.zig
index 6f418b0a97eb..1eaec5c098bf 100644
--- a/lib/std/net.zig
+++ b/lib/std/net.zig
@@ -1263,7 +1263,7 @@ fn linuxLookupNameFromHosts(
         },
         else => |e| return e,
     }) |line| {
-        var split_it = mem.split(u8, line, "#");
+        var split_it = mem.splitScalar(u8, line, '#');
         const no_comment_line = split_it.first();
 
         var line_it = mem.tokenizeAny(u8, no_comment_line, " \t");
@@ -1465,7 +1465,7 @@ fn getResolvConf(allocator: mem.Allocator, rc: *ResolvConf) !void {
         else => |e| return e,
     }) |line| {
         const no_comment_line = no_comment_line: {
-            var split = mem.split(u8, line, "#");
+            var split = mem.splitScalar(u8, line, '#');
             break :no_comment_line split.first();
         };
         var line_it = mem.tokenizeAny(u8, no_comment_line, " \t");
@@ -1473,7 +1473,7 @@ fn getResolvConf(allocator: mem.Allocator, rc: *ResolvConf) !void {
         const token = line_it.next() orelse continue;
         if (mem.eql(u8, token, "options")) {
             while (line_it.next()) |sub_tok| {
-                var colon_it = mem.split(u8, sub_tok, ":");
+                var colon_it = mem.splitScalar(u8, sub_tok, ':');
                 const name = colon_it.first();
                 const value_txt = colon_it.next() orelse continue;
                 const value = std.fmt.parseInt(u8, value_txt, 10) catch |err| switch (err) {
diff --git a/lib/std/process.zig b/lib/std/process.zig
index c33fd92db645..80be7051876f 100644
--- a/lib/std/process.zig
+++ b/lib/std/process.zig
@@ -310,7 +310,7 @@ pub fn getEnvMap(allocator: Allocator) !EnvMap {
 
         for (environ) |env| {
             const pair = mem.sliceTo(env, 0);
-            var parts = mem.split(u8, pair, "=");
+            var parts = mem.splitScalar(u8, pair, '=');
             const key = parts.first();
             const value = parts.rest();
             try result.put(key, value);
diff --git a/lib/std/zig/CrossTarget.zig b/lib/std/zig/CrossTarget.zig
index 93b6d97d7540..d072a4dbaded 100644
--- a/lib/std/zig/CrossTarget.zig
+++ b/lib/std/zig/CrossTarget.zig
@@ -239,7 +239,7 @@ pub fn parse(args: ParseOptions) !CrossTarget {
         .dynamic_linker = DynamicLinker.init(args.dynamic_linker),
     };
 
-    var it = mem.split(u8, args.arch_os_abi, "-");
+    var it = mem.splitScalar(u8, args.arch_os_abi, '-');
     const arch_name = it.first();
     const arch_is_native = mem.eql(u8, arch_name, "native");
     if (!arch_is_native) {
@@ -257,7 +257,7 @@ pub fn parse(args: ParseOptions) !CrossTarget {
 
     const opt_abi_text = it.next();
     if (opt_abi_text) |abi_text| {
-        var abi_it = mem.split(u8, abi_text, ".");
+        var abi_it = mem.splitScalar(u8, abi_text, '.');
         const abi = std.meta.stringToEnum(Target.Abi, abi_it.first()) orelse
             return error.UnknownApplicationBinaryInterface;
         result.abi = abi;
@@ -343,7 +343,7 @@ pub fn parse(args: ParseOptions) !CrossTarget {
 /// This is intended to be used if the API user of CrossTarget needs to learn the
 /// target CPU architecture in order to fully populate `ParseOptions`.
 pub fn parseCpuArch(args: ParseOptions) ?Target.Cpu.Arch {
-    var it = mem.split(u8, args.arch_os_abi, "-");
+    var it = mem.splitScalar(u8, args.arch_os_abi, '-');
     const arch_name = it.first();
     const arch_is_native = mem.eql(u8, arch_name, "native");
     if (arch_is_native) {
@@ -645,7 +645,7 @@ pub fn updateCpuFeatures(self: CrossTarget, set: *Target.Cpu.Feature.Set) void {
 }
 
 fn parseOs(result: *CrossTarget, diags: *ParseOptions.Diagnostics, text: []const u8) !void {
-    var it = mem.split(u8, text, ".");
+    var it = mem.splitScalar(u8, text, '.');
     const os_name = it.first();
     diags.os_name = os_name;
     const os_is_native = mem.eql(u8, os_name, "native");
@@ -706,7 +706,7 @@ fn parseOs(result: *CrossTarget, diags: *ParseOptions.Diagnostics, text: []const
         .linux,
         .dragonfly,
         => {
-            var range_it = mem.split(u8, version_text, "...");
+            var range_it = mem.splitFull(u8, version_text, "...");
 
             const min_text = range_it.next().?;
             const min_ver = SemVer.parse(min_text) catch |err| switch (err) {
@@ -726,7 +726,7 @@ fn parseOs(result: *CrossTarget, diags: *ParseOptions.Diagnostics, text: []const
         },
 
         .windows => {
-            var range_it = mem.split(u8, version_text, "...");
+            var range_it = mem.splitFull(u8, version_text, "...");
 
             const min_text = range_it.first();
             const min_ver = std.meta.stringToEnum(Target.Os.WindowsVersion, min_text) orelse
diff --git a/lib/std/zig/ErrorBundle.zig b/lib/std/zig/ErrorBundle.zig
index ffe748203e82..fe0ae3c0f66e 100644
--- a/lib/std/zig/ErrorBundle.zig
+++ b/lib/std/zig/ErrorBundle.zig
@@ -294,7 +294,7 @@ fn renderErrorMessageToWriter(
 ///
 /// This is used to split the message in `@compileError("hello\nworld")` for example.
 fn writeMsg(eb: ErrorBundle, err_msg: ErrorMessage, stderr: anytype, indent: usize) !void {
-    var lines = std.mem.split(u8, eb.nullTerminatedString(err_msg.msg), "\n");
+    var lines = std.mem.splitScalar(u8, eb.nullTerminatedString(err_msg.msg), '\n');
     while (lines.next()) |line| {
         try stderr.writeAll(line);
         if (lines.index == null) break;
diff --git a/lib/std/zig/render.zig b/lib/std/zig/render.zig
index 367d06f7c63b..22393b1ceaf6 100644
--- a/lib/std/zig/render.zig
+++ b/lib/std/zig/render.zig
@@ -1990,7 +1990,7 @@ fn renderArrayInit(
             if (!expr_newlines[i]) {
                 try ais.writer().writeAll(expr_text);
             } else {
-                var by_line = std.mem.split(u8, expr_text, "\n");
+                var by_line = std.mem.splitScalar(u8, expr_text, '\n');
                 var last_line_was_empty = false;
                 try ais.writer().writeAll(by_line.first());
                 while (by_line.next()) |line| {
diff --git a/lib/std/zig/system/NativeTargetInfo.zig b/lib/std/zig/system/NativeTargetInfo.zig
index 808a1bda8d35..5cbc274ffd38 100644
--- a/lib/std/zig/system/NativeTargetInfo.zig
+++ b/lib/std/zig/system/NativeTargetInfo.zig
@@ -556,7 +556,7 @@ fn glibcVerFromSoFile(file: fs.File) !std.builtin.Version {
     const dynstr_size = @intCast(usize, dynstr.size);
     const dynstr_bytes = buf[0..dynstr_size];
     _ = try preadMin(file, dynstr_bytes, dynstr.offset, dynstr_bytes.len);
-    var it = mem.split(u8, dynstr_bytes, &.{0});
+    var it = mem.splitScalar(u8, dynstr_bytes, 0);
     var max_ver: std.builtin.Version = .{ .major = 2, .minor = 2, .patch = 5 };
     while (it.next()) |s| {
         if (mem.startsWith(u8, s, "GLIBC_2.")) {
diff --git a/src/Autodoc.zig b/src/Autodoc.zig
index f73e718a4d73..d4a8446705a1 100644
--- a/src/Autodoc.zig
+++ b/src/Autodoc.zig
@@ -4839,7 +4839,7 @@ fn findGuidePaths(self: *Autodoc, file: *File, str: []const u8) ![]const u8 {
 
     // TODO: this algo is kinda inefficient
 
-    var it = std.mem.split(u8, str, "\n");
+    var it = std.mem.splitScalar(u8, str, '\n');
     while (it.next()) |line| {
         const trimmed_line = std.mem.trim(u8, line, " ");
         if (std.mem.startsWith(u8, trimmed_line, guide_prefix)) {
diff --git a/src/Compilation.zig b/src/Compilation.zig
index a5b785cc67ad..818fe371b622 100644
--- a/src/Compilation.zig
+++ b/src/Compilation.zig
@@ -4636,7 +4636,7 @@ pub fn hasSharedLibraryExt(filename: []const u8) bool {
         return true;
     }
     // Look for .so.X, .so.X.Y, .so.X.Y.Z
-    var it = mem.split(u8, filename, ".");
+    var it = mem.splitScalar(u8, filename, '.');
     _ = it.first();
     var so_txt = it.next() orelse return false;
     while (!mem.eql(u8, so_txt, "so")) {
@@ -5016,14 +5016,14 @@ fn parseLldStderr(comp: *Compilation, comptime prefix: []const u8, stderr: []con
     defer context_lines.deinit();
 
     var current_err: ?*LldError = null;
-    var lines = mem.split(u8, stderr, std.cstr.line_sep);
+    var lines = mem.splitFull(u8, stderr, std.cstr.line_sep);
     while (lines.next()) |line| {
         if (mem.startsWith(u8, line, prefix ++ ":")) {
             if (current_err) |err| {
                 err.context_lines = try context_lines.toOwnedSlice();
             }
 
-            var split = std.mem.split(u8, line, "error: ");
+            var split = std.mem.splitFull(u8, line, "error: ");
             _ = split.first();
 
             const duped_msg = try std.fmt.allocPrint(comp.gpa, "{s}: {s}", .{ prefix, split.rest() });
diff --git a/src/libc_installation.zig b/src/libc_installation.zig
index a62da6b9c7df..355c3bad8dcd 100644
--- a/src/libc_installation.zig
+++ b/src/libc_installation.zig
@@ -63,7 +63,7 @@ pub const LibCInstallation = struct {
         var it = std.mem.tokenizeScalar(u8, contents, '\n');
         while (it.next()) |line| {
             if (line.len == 0 or line[0] == '#') continue;
-            var line_it = std.mem.split(u8, line, "=");
+            var line_it = std.mem.splitScalar(u8, line, '=');
             const name = line_it.first();
             const value = line_it.rest();
             inline for (fields, 0..) |field, i| {
diff --git a/src/link/MachO/Dylib.zig b/src/link/MachO/Dylib.zig
index 863f1e805a36..971706dae628 100644
--- a/src/link/MachO/Dylib.zig
+++ b/src/link/MachO/Dylib.zig
@@ -91,7 +91,7 @@ pub const Id = struct {
         var out: u32 = 0;
         var values: [3][]const u8 = undefined;
 
-        var split = mem.split(u8, string, ".");
+        var split = mem.splitScalar(u8, string, '.');
         var count: u4 = 0;
         while (split.next()) |value| {
             if (count > 2) {
diff --git a/src/main.zig b/src/main.zig
index 45b0cf30b84c..bcc5f2941a47 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -973,7 +973,7 @@ fn buildOutputType(
                         }
                     } else if (mem.eql(u8, arg, "--mod")) {
                         const info = args_iter.nextOrFatal();
-                        var info_it = mem.split(u8, info, ":");
+                        var info_it = mem.splitScalar(u8, info, ':');
                         const mod_name = info_it.next() orelse fatal("expected non-empty argument after {s}", .{arg});
                         const deps_str = info_it.next() orelse fatal("expected 'name:deps:path' after {s}", .{arg});
                         const root_src_orig = info_it.rest();
@@ -1173,7 +1173,7 @@ fn buildOutputType(
                         } else {
                             if (build_options.omit_pkg_fetching_code) unreachable;
                             // example: --listen 127.0.0.1:9000
-                            var it = std.mem.split(u8, next_arg, ":");
+                            var it = std.mem.splitScalar(u8, next_arg, ':');
                             const host = it.next().?;
                             const port_text = it.next() orelse "14735";
                             const port = std.fmt.parseInt(u16, port_text, 10) catch |err|
@@ -1670,7 +1670,7 @@ fn buildOutputType(
                     },
                     .rdynamic => rdynamic = true,
                     .wl => {
-                        var split_it = mem.split(u8, it.only_arg, ",");
+                        var split_it = mem.splitScalar(u8, it.only_arg, ',');
                         while (split_it.next()) |linker_arg| {
                             // Handle nested-joined args like `-Wl,-rpath=foo`.
                             // Must be prefixed with 1 or 2 dashes.
@@ -2180,17 +2180,17 @@ fn buildOutputType(
                     const next_arg = linker_args_it.nextOrFatal();
                     try symbol_wrap_set.put(arena, next_arg, {});
                 } else if (mem.startsWith(u8, arg, "/subsystem:")) {
-                    var split_it = mem.splitBackwards(u8, arg, ":");
+                    var split_it = mem.splitBackwardsScalar(u8, arg, ':');
                     subsystem = try parseSubSystem(split_it.first());
                 } else if (mem.startsWith(u8, arg, "/implib:")) {
-                    var split_it = mem.splitBackwards(u8, arg, ":");
+                    var split_it = mem.splitBackwardsScalar(u8, arg, ':');
                     emit_implib = .{ .yes = split_it.first() };
                     emit_implib_arg_provided = true;
                 } else if (mem.startsWith(u8, arg, "/pdb:")) {
-                    var split_it = mem.splitBackwards(u8, arg, ":");
+                    var split_it = mem.splitBackwardsScalar(u8, arg, ':');
                     pdb_out_path = split_it.first();
                 } else if (mem.startsWith(u8, arg, "/version:")) {
-                    var split_it = mem.splitBackwards(u8, arg, ":");
+                    var split_it = mem.splitBackwardsScalar(u8, arg, ':');
                     const version_arg = split_it.first();
                     version = std.builtin.Version.parse(version_arg) catch |err| {
                         fatal("unable to parse /version '{s}': {s}", .{ arg, @errorName(err) });
@@ -3531,7 +3531,7 @@ const ModuleDepIterator = struct {
     split: mem.SplitIterator(u8),
 
     fn init(deps_str: []const u8) ModuleDepIterator {
-        return .{ .split = mem.split(u8, deps_str, ",") };
+        return .{ .split = mem.splitScalar(u8, deps_str, ',') };
     }
 
     const Dependency = struct {
diff --git a/test/src/Cases.zig b/test/src/Cases.zig
index eec03737c719..743fb54ac5f0 100644
--- a/test/src/Cases.zig
+++ b/test/src/Cases.zig
@@ -877,7 +877,7 @@ const TestManifest = struct {
             if (trimmed.len == 0) break;
 
             // Parse key=value(s)
-            var kv_it = std.mem.split(u8, trimmed, "=");
+            var kv_it = std.mem.splitScalar(u8, trimmed, '=');
             const key = kv_it.first();
             try manifest.config_map.putNoClobber(key, kv_it.next() orelse return error.MissingValuesForConfig);
         }
@@ -895,7 +895,7 @@ const TestManifest = struct {
     ) ConfigValueIterator(T) {
         const bytes = self.config_map.get(key) orelse TestManifestConfigDefaults.get(self.type, key);
         return ConfigValueIterator(T){
-            .inner = std.mem.split(u8, bytes, ","),
+            .inner = std.mem.splitScalar(u8, bytes, ','),
         };
     }
 
@@ -1399,7 +1399,7 @@ fn runOneCase(
                 // Render the expected lines into a string that we can compare verbatim.
                 var expected_generated = std.ArrayList(u8).init(arena);
 
-                var actual_line_it = std.mem.split(u8, actual_stderr.items, "\n");
+                var actual_line_it = std.mem.splitScalar(u8, actual_stderr.items, '\n');
                 for (expected_errors) |expect_line| {
                     const actual_line = actual_line_it.next() orelse {
                         try expected_generated.appendSlice(expect_line);
diff --git a/test/src/check-stack-trace.zig b/test/src/check-stack-trace.zig
index bb1db55076e0..9856b5738e5a 100644
--- a/test/src/check-stack-trace.zig
+++ b/test/src/check-stack-trace.zig
@@ -27,7 +27,7 @@ pub fn main() !void {
         var buf = std.ArrayList(u8).init(arena);
         defer buf.deinit();
         if (stderr.len != 0 and stderr[stderr.len - 1] == '\n') stderr = stderr[0 .. stderr.len - 1];
-        var it = mem.split(u8, stderr, "\n");
+        var it = mem.splitScalar(u8, stderr, '\n');
         process_lines: while (it.next()) |line| {
             if (line.len == 0) continue;
 
diff --git a/tools/gen_outline_atomics.zig b/tools/gen_outline_atomics.zig
index c04591d03279..0cfdacffd1a3 100644
--- a/tools/gen_outline_atomics.zig
+++ b/tools/gen_outline_atomics.zig
@@ -88,7 +88,7 @@ fn writeFunction(
         \\    asm volatile (
         \\
     );
-    var iter = std.mem.split(u8, body, "\n");
+    var iter = std.mem.splitScalar(u8, body, '\n');
     while (iter.next()) |line| {
         try w.writeAll("        \\\\");
         try w.writeAll(line);
diff --git a/tools/update_crc_catalog.zig b/tools/update_crc_catalog.zig
index 034b7afc9dd8..2fdb9b030f6a 100644
--- a/tools/update_crc_catalog.zig
+++ b/tools/update_crc_catalog.zig
@@ -78,7 +78,7 @@ pub fn main() anyerror!void {
         var residue: []const u8 = undefined;
         var name: []const u8 = undefined;
 
-        var it = mem.split(u8, line, "  ");
+        var it = mem.splitFull(u8, line, "  ");
         while (it.next()) |property| {
             const i = mem.indexOf(u8, property, "=").?;
             const key = property[0..i];
diff --git a/tools/update_spirv_features.zig b/tools/update_spirv_features.zig
index bb859ed5b453..7e8c649d4dbf 100644
--- a/tools/update_spirv_features.zig
+++ b/tools/update_spirv_features.zig
@@ -19,7 +19,7 @@ const Version = struct {
     minor: u32,
 
     fn parse(str: []const u8) !Version {
-        var it = std.mem.split(u8, str, ".");
+        var it = std.mem.splitScalar(u8, str, '.');
 
         const major = it.first();
         const minor = it.next() orelse return error.InvalidVersion;