diff --git a/.github/workflows/benchmarks.yml b/.github/workflows/benchmarks.yml
new file mode 100644
index 00000000..2adadd58
--- /dev/null
+++ b/.github/workflows/benchmarks.yml
@@ -0,0 +1,63 @@
+name: Benchmarks
+
+# spell-checker:ignore codspeed dtolnay Swatinem sccache
+
+on:
+  pull_request:
+  push:
+    branches:
+      - '*'
+
+permissions:
+  contents: read # to fetch code (actions/checkout)
+
+# End the current execution if there is a new changeset in the PR.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ github.ref != 'refs/heads/main' }}
+
+jobs:
+  benchmarks:
+    name: Run benchmarks (CodSpeed)
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        benchmark-target:
+          - { package: sed }
+    steps:
+      - uses: actions/checkout@v6
+        with:
+          persist-credentials: false
+
+      - name: Install system dependencies
+        shell: bash
+        run: |
+          sudo apt-get -y update
+
+      - uses: dtolnay/rust-toolchain@stable
+
+      - uses: Swatinem/rust-cache@v2
+
+      - name: Run sccache-cache
+        uses: mozilla-actions/sccache-action@v0.0.9
+
+      - name: Install cargo-codspeed
+        shell: bash
+        run: cargo install cargo-codspeed --locked
+
+      - name: Build benchmarks for ${{ matrix.benchmark-target.package }}
+        shell: bash
+        run: |
+          echo "Building benchmarks for ${{ matrix.benchmark-target.package }}"
+          cargo codspeed build -p ${{ matrix.benchmark-target.package }}
+
+      - name: Run benchmarks for ${{ matrix.benchmark-target.package }}
+        uses: CodSpeedHQ/action@v4
+        env:
+          CODSPEED_LOG: debug
+        with:
+          mode: simulation
+          run: |
+            echo "Running benchmarks for ${{ matrix.benchmark-target.package }}"
+            cargo codspeed run -p ${{ matrix.benchmark-target.package }} > /dev/null
+          token: ${{ secrets.CODSPEED_TOKEN }}
diff --git a/Cargo.lock b/Cargo.lock
index cdfc4be8..4f72f82f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -70,6 +70,21 @@ dependencies = [
  "windows-sys 0.59.0",
 ]
 
+[[package]]
+name = "anyhow"
+version = "1.0.100"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a23eb6b1614318a8071c9b2521f36b424b2c83db5eb3a0fead4a6c0809af6e61"
+
+[[package]]
+name = "approx"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cab112f0a86d568ea0e627cc1d6be74a1e9cd55214684db5561995f6dad897c6"
+dependencies = [
+ "num-traits",
+]
+
 [[package]]
 name = "assert_fs"
 version = "1.1.3"
@@ -207,12 +222,88 @@ dependencies = [
  "roff",
 ]
 
+[[package]]
+name = "codspeed"
+version = "4.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c3b847e05a34be5c38f3f2a5052178a3bd32e6b5702f3ea775efde95c483a539"
+dependencies = [
+ "anyhow",
+ "cc",
+ "colored",
+ "getrandom 0.2.16",
+ "glob",
+ "libc",
+ "nix",
+ "serde",
+ "serde_json",
+ "statrs",
+]
+
+[[package]]
+name = "codspeed-divan-compat"
+version = "4.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f0f0e9fe5eaa39995ec35e46407f7154346cc25bd1300c64c21636f3d00cb2cc"
+dependencies = [
+ "clap",
+ "codspeed",
+ "codspeed-divan-compat-macros",
+ "codspeed-divan-compat-walltime",
+ "regex",
+]
+
+[[package]]
+name = "codspeed-divan-compat-macros"
+version = "4.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "88c8babf2a40fd2206a2e030cf020d0d58144cd56e1dc408bfba02cdefb08b4f"
+dependencies = [
+ "divan-macros",
+ "itertools",
+ "proc-macro-crate",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "codspeed-divan-compat-walltime"
+version = "4.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7f26092328e12a36704ffc552f379c6405dd94d3149970b79b22d371717c2aae"
+dependencies = [
+ "cfg-if",
+ "clap",
+ "codspeed",
+ "condtype",
+ "divan-macros",
+ "libc",
+ "regex-lite",
+]
+
 [[package]]
 name = "colorchoice"
 version = "1.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5b63caa9aa9397e2d9480a9b13673856c78d8ac123288526c37d7839f2a86990"
 
+[[package]]
+name = "colored"
+version = "2.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "117725a109d387c937a1533ce01b450cbde6b88abceea8473c4d7a85853cda3c"
+dependencies = [
+ "lazy_static",
+ "windows-sys 0.59.0",
+]
+
+[[package]]
+name = "condtype"
+version = "1.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "baf0a07a401f374238ab8e2f11a104d2851bf9ce711ec69804834de8af45c7af"
+
 [[package]]
 name = "core-foundation-sys"
 version = "0.8.7"
@@ -292,6 +383,17 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "divan-macros"
+version = "0.1.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8dc51d98e636f5e3b0759a39257458b22619cac7e96d932da6eeb052891bb67c"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "dns-lookup"
 version = "3.0.0"
@@ -325,6 +427,18 @@ version = "0.0.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f678cf4a922c215c63e0de95eb1ff08a958a81d47e485cf9da1e27bf6305cfa5"
 
+[[package]]
+name = "either"
+version = "1.15.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "48c757948c5ede0e46177b7add2e67155f70e33c07fea8284df6576da70b3719"
+
+[[package]]
+name = "equivalent"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "877a4ace8713b0bcf2a4e7eec82529c029f1d0619886d18145fea96c3ffe5c0f"
+
 [[package]]
 name = "errno"
 version = "0.3.12"
@@ -406,6 +520,17 @@ dependencies = [
  "thiserror",
 ]
 
+[[package]]
+name = "getrandom"
+version = "0.2.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "335ff9f135e4384c8150d6f27c6daed433577f86b4750418338c01a1a2528592"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi 0.11.1+wasi-snapshot-preview1",
+]
+
 [[package]]
 name = "getrandom"
 version = "0.3.3"
@@ -415,7 +540,7 @@ dependencies = [
  "cfg-if",
  "libc",
  "r-efi",
- "wasi",
+ "wasi 0.14.2+wasi-0.2.4",
 ]
 
 [[package]]
@@ -448,6 +573,12 @@ dependencies = [
  "walkdir",
 ]
 
+[[package]]
+name = "hashbrown"
+version = "0.16.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "841d1cc9bed7f9236f321df977030373f4a4163ae1a7dbfe1a51a2c1a51d9100"
+
 [[package]]
 name = "iana-time-zone"
 version = "0.1.63"
@@ -488,6 +619,16 @@ dependencies = [
  "winapi-util",
 ]
 
+[[package]]
+name = "indexmap"
+version = "2.12.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0ad4bb2b565bca0645f4d68c5c9af97fba094e9791da685bf83cb5f3ce74acf2"
+dependencies = [
+ "equivalent",
+ "hashbrown",
+]
+
 [[package]]
 name = "intl-memoizer"
 version = "0.5.3"
@@ -513,6 +654,15 @@ version = "1.70.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7943c866cc5cd64cbc25b2e01621d07fa8eb2a1a23160ee81ce38704e97b8ecf"
 
+[[package]]
+name = "itertools"
+version = "0.14.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2b192c782037fadd9cfa75548310488aabdbf3d2da73885b31bd0abd03351285"
+dependencies = [
+ "either",
+]
+
 [[package]]
 name = "itoa"
 version = "1.0.15"
@@ -570,6 +720,12 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "lazy_static"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"
+
 [[package]]
 name = "libc"
 version = "0.2.178"
@@ -803,6 +959,15 @@ dependencies = [
  "yansi",
 ]
 
+[[package]]
+name = "proc-macro-crate"
+version = "3.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "219cb19e96be00ab2e37d6e299658a0cfa83e52429179969b0f0121b4ac46983"
+dependencies = [
+ "toml_edit",
+]
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.95"
@@ -853,7 +1018,7 @@ version = "0.9.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "99d9a13982dcf210057a8a78572b2217b667c3beacbf3a0d8b454f6f82837d38"
 dependencies = [
- "getrandom",
+ "getrandom 0.3.3",
 ]
 
 [[package]]
@@ -879,6 +1044,12 @@ dependencies = [
  "regex-syntax",
 ]
 
+[[package]]
+name = "regex-lite"
+version = "0.1.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8d942b98df5e658f56f20d592c7f868833fe38115e65c33003d8cd224b0155da"
+
 [[package]]
 name = "regex-syntax"
 version = "0.8.5"
@@ -925,6 +1096,12 @@ version = "1.0.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8a0d197bd2c9dc6e53b84da9556a69ba4cdfab8619eb41a8bd1cc2027a0f6b1d"
 
+[[package]]
+name = "ryu"
+version = "1.0.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "28d3b2b1366ec20994f1fd18c3c594f05c5dd4bc44d8bb0c1c632c8d6829481f"
+
 [[package]]
 name = "same-file"
 version = "1.0.6"
@@ -943,6 +1120,7 @@ dependencies = [
  "clap",
  "clap_complete",
  "clap_mangen",
+ "codspeed-divan-compat",
  "ctor",
  "fancy-regex",
  "libc",
@@ -973,24 +1151,47 @@ checksum = "0f7d95a54511e0c7be3f51e8867aa8cf35148d7b9445d44de2f943e2b206e749"
 
 [[package]]
 name = "serde"
-version = "1.0.219"
+version = "1.0.228"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5f0e2c6ed6606019b4e29e69dbaba95b11854410e5347d525002456dbbb786b6"
+checksum = "9a8e94ea7f378bd32cbbd37198a4a91436180c5bb472411e48b5ec2e2124ae9e"
+dependencies = [
+ "serde_core",
+ "serde_derive",
+]
+
+[[package]]
+name = "serde_core"
+version = "1.0.228"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "41d385c7d4ca58e59fc732af25c3983b67ac852c1a25000afe1175de458b67ad"
 dependencies = [
  "serde_derive",
 ]
 
 [[package]]
 name = "serde_derive"
-version = "1.0.219"
+version = "1.0.228"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5b0276cf7f2c73365f7157c8123c21cd9a50fbbd844757af28ca1f5925fc2a00"
+checksum = "d540f220d3187173da220f885ab66608367b6574e925011a9353e4badda91d79"
 dependencies = [
  "proc-macro2",
  "quote",
  "syn",
 ]
 
+[[package]]
+name = "serde_json"
+version = "1.0.145"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "402a6f66d8c709116cf22f558eab210f5a50187f702eb4d7e5ef38d9a7f1c79c"
+dependencies = [
+ "itoa",
+ "memchr",
+ "ryu",
+ "serde",
+ "serde_core",
+]
+
 [[package]]
 name = "shlex"
 version = "1.3.0"
@@ -1025,6 +1226,16 @@ dependencies = [
  "windows-sys 0.59.0",
 ]
 
+[[package]]
+name = "statrs"
+version = "0.18.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2a3fe7c28c6512e766b0874335db33c94ad7b8f9054228ae1c2abd47ce7d335e"
+dependencies = [
+ "approx",
+ "num-traits",
+]
+
 [[package]]
 name = "strsim"
 version = "0.11.1"
@@ -1063,7 +1274,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2d31c77bdf42a745371d260a26ca7163f1e0924b64afa0b688e61b5a9fa02f16"
 dependencies = [
  "fastrand",
- "getrandom",
+ "getrandom 0.3.3",
  "once_cell",
  "rustix",
  "windows-sys 0.60.2",
@@ -1160,6 +1371,36 @@ dependencies = [
  "zerovec",
 ]
 
+[[package]]
+name = "toml_datetime"
+version = "0.7.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f2cdb639ebbc97961c51720f858597f7f24c4fc295327923af55b74c3c724533"
+dependencies = [
+ "serde_core",
+]
+
+[[package]]
+name = "toml_edit"
+version = "0.23.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5d7cbc3b4b49633d57a0509303158ca50de80ae32c265093b24c414705807832"
+dependencies = [
+ "indexmap",
+ "toml_datetime",
+ "toml_parser",
+ "winnow",
+]
+
+[[package]]
+name = "toml_parser"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c0cbe268d35bdb4bb5a56a2de88d0ad0eb70af5384a99d648cd4b3d04039800e"
+dependencies = [
+ "winnow",
+]
+
 [[package]]
 name = "type-map"
 version = "0.5.1"
@@ -1218,6 +1459,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b5eddd390f3fdef74f104a948559e6de29203f60f8f563c8c9f528cd4c88ee78"
 dependencies = [
  "clap",
+ "codspeed-divan-compat",
  "dns-lookup",
  "fluent",
  "fluent-bundle",
@@ -1227,6 +1469,7 @@ dependencies = [
  "nix",
  "os_display",
  "phf",
+ "tempfile",
  "thiserror",
  "time",
  "unic-langid",
@@ -1272,6 +1515,12 @@ dependencies = [
  "winapi-util",
 ]
 
+[[package]]
+name = "wasi"
+version = "0.11.1+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ccf3ec651a847eb01de73ccad15eb7d99f80485de043efb2f370cd654f4ea44b"
+
 [[package]]
 name = "wasi"
 version = "0.14.2+wasi-0.2.4"
@@ -1642,6 +1891,15 @@ version = "0.53.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "271414315aff87387382ec3d271b52d7ae78726f5d44ac98b4f4030c91880486"
 
+[[package]]
+name = "winnow"
+version = "0.7.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5a5364e9d77fcdeeaa6062ced926ee3381faa2ee02d3eb83a5c27a8825540829"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "wit-bindgen-rt"
 version = "0.39.0"
diff --git a/Cargo.toml b/Cargo.toml
index 9b939314..6db28809 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -36,6 +36,7 @@ chrono = { version = "0.4.37", default-features = false, features = [
 clap = { version = "4.4", features = ["wrap_help", "cargo"] }
 clap_complete = "4.5"
 clap_mangen = "0.2"
+divan = { package = "codspeed-divan-compat", version = "4.0.5" }
 fancy-regex = "0.17.0"
 libc = "0.2.153"
 memchr = "2.7.4"
@@ -75,12 +76,13 @@ uucore = { workspace = true }
 
 [dev-dependencies]
 chrono = { workspace = true }
+divan = { workspace = true }
 libc = { workspace = true }
 pretty_assertions = "1"
 rand = { workspace = true }
 regex = { workspace = true }
 tempfile = { workspace = true }
-uucore = { workspace = true, features = ["entries", "process", "signals"] }
+uucore = { workspace = true, features = ["entries", "process", "signals", "benchmark"] }
 uutests = "0.5.0"
 
 [target.'cfg(unix)'.dev-dependencies]
@@ -104,6 +106,10 @@ name = "uudoc"
 path = "src/bin/uudoc.rs"
 required-features = ["uudoc"]
 
+[[bench]]
+name = "sed_bench"
+harness = false
+
 # The default release profile. It contains all optimizations, without
 # sacrificing debug info. With this profile (like in the standard
 # release profile), the debug info and the stack traces will still be available.
diff --git a/benches/sed_bench.rs b/benches/sed_bench.rs
new file mode 100644
index 00000000..58ac7bc6
--- /dev/null
+++ b/benches/sed_bench.rs
@@ -0,0 +1,262 @@
+// Definitions for the compiled code data structures
+//
+// SPDX-License-Identifier: MIT
+//
+// This file is part of the uutils sed package.
+// It is licensed under the MIT License.
+// For the full copyright and license information, please view the LICENSE
+// file that was distributed with this source code.
+
+use divan::{Bencher, black_box};
+use sed::sed::uumain;
+use uucore::benchmark::{create_test_file, run_util_function};
+
+/// Benchmark no-op on short lines
+#[divan::bench]
+fn no_op_short(bencher: Bencher) {
+    let temp_dir = tempfile::tempdir().unwrap();
+    let mut data = Vec::new();
+    for i in 0..10_000_000 {
+        data.extend_from_slice(format!("{}\n", i).as_bytes());
+    }
+    let file_path = create_test_file(&data, temp_dir.path());
+    let file_path_str = file_path.to_str().unwrap();
+
+    bencher.bench(|| {
+        black_box(run_util_function(uumain, &["", file_path_str]));
+    });
+}
+
+/// Benchmark access log no-op
+#[divan::bench]
+fn access_log_no_op(bencher: Bencher) {
+    let temp_dir = tempfile::tempdir().unwrap();
+    let mut data = Vec::new();
+    for i in 0..5_000_000 {
+        let line = format!(
+            "192.168.{}.{} - - [01/Jan/2024:00:00:00 +0000] \"GET /index.html HTTP/1.1\" 200 1234 \"-\" \"Mozilla/5.0\"\n",
+            (i / 256) % 256,
+            i % 256
+        );
+        data.extend_from_slice(line.as_bytes());
+    }
+    let file_path = create_test_file(&data, temp_dir.path());
+    let file_path_str = file_path.to_str().unwrap();
+
+    bencher.bench(|| {
+        black_box(run_util_function(uumain, &["", file_path_str]));
+    });
+}
+
+/// Benchmark access log no substitution
+#[divan::bench]
+fn access_log_no_subst(bencher: Bencher) {
+    let temp_dir = tempfile::tempdir().unwrap();
+    let mut data = Vec::new();
+    for i in 0..1_000_000 {
+        let line = format!(
+            "192.168.{}.{} - - [01/Jan/2024:00:00:00 +0000] \"GET /index.html HTTP/1.1\" 200 1234 \"-\" \"Mozilla/5.0\"\n",
+            (i / 256) % 256,
+            i % 256
+        );
+        data.extend_from_slice(line.as_bytes());
+    }
+    let file_path = create_test_file(&data, temp_dir.path());
+    let file_path_str = file_path.to_str().unwrap();
+
+    bencher.bench(|| {
+        black_box(run_util_function(
+            uumain,
+            &["s/Chrome/Chromium/", file_path_str],
+        ));
+    });
+}
+
+/// Benchmark access log substitution
+#[divan::bench]
+fn access_log_subst(bencher: Bencher) {
+    let temp_dir = tempfile::tempdir().unwrap();
+    let mut data = Vec::new();
+    for i in 0..1_000_000 {
+        let line = format!(
+            "192.168.{}.{} - - [01/Jan/2024:00:00:00 +0000] \"GET /index.html HTTP/1.1\" 200 1234 \"-\" \"Mozilla/5.0\"\n",
+            (i / 256) % 256,
+            i % 256
+        );
+        data.extend_from_slice(line.as_bytes());
+    }
+    let file_path = create_test_file(&data, temp_dir.path());
+    let file_path_str = file_path.to_str().unwrap();
+
+    bencher.bench(|| {
+        black_box(run_util_function(
+            uumain,
+            &["s/Mozilla/Chromium/", file_path_str],
+        ));
+    });
+}
+
+/// Benchmark access log no deletion
+#[divan::bench]
+fn access_log_no_del(bencher: Bencher) {
+    let temp_dir = tempfile::tempdir().unwrap();
+    let mut data = Vec::new();
+    for i in 0..1_000_000 {
+        let line = format!(
+            "192.168.{}.{} - - [01/Jan/2024:00:00:00 +0000] \"GET /index.html HTTP/1.1\" 200 1234 \"-\" \"Mozilla/5.0\"\n",
+            (i / 256) % 256,
+            i % 256
+        );
+        data.extend_from_slice(line.as_bytes());
+    }
+    let file_path = create_test_file(&data, temp_dir.path());
+    let file_path_str = file_path.to_str().unwrap();
+
+    bencher.bench(|| {
+        black_box(run_util_function(uumain, &["/Chrome/d", file_path_str]));
+    });
+}
+
+/// Benchmark access log full deletion
+#[divan::bench]
+fn access_log_all_del(bencher: Bencher) {
+    let temp_dir = tempfile::tempdir().unwrap();
+    let mut data = Vec::new();
+    for i in 0..1_000_000 {
+        let line = format!(
+            "192.168.{}.{} - - [01/Jan/2024:00:00:00 +0000] \"GET /index.html HTTP/1.1\" 200 1234 \"-\" \"Mozilla/5.0\"\n",
+            (i / 256) % 256,
+            i % 256
+        );
+        data.extend_from_slice(line.as_bytes());
+    }
+    let file_path = create_test_file(&data, temp_dir.path());
+    let file_path_str = file_path.to_str().unwrap();
+
+    bencher.bench(|| {
+        black_box(run_util_function(uumain, &["/Mozilla/d", file_path_str]));
+    });
+}
+
+/// Benchmark transliteration
+#[divan::bench]
+fn access_log_translit(bencher: Bencher) {
+    let temp_dir = tempfile::tempdir().unwrap();
+    let mut data = Vec::new();
+    for i in 0..500_000 {
+        let line = format!(
+            "192.168.{}.{} - - [01/Jan/2024:00:00:00 +0000] \"GET /index.html HTTP/1.1\" 200 1234 \"-\" \"Mozilla/5.0\"\n",
+            (i / 256) % 256,
+            i % 256
+        );
+        data.extend_from_slice(line.as_bytes());
+    }
+    let file_path = create_test_file(&data, temp_dir.path());
+    let file_path_str = file_path.to_str().unwrap();
+
+    bencher.bench(|| {
+        black_box(run_util_function(
+            uumain,
+            &["y/0123456789/9876543210/", file_path_str],
+        ));
+    });
+}
+
+/// Benchmark text append
+#[divan::bench]
+fn access_log_append(bencher: Bencher) {
+    let temp_dir = tempfile::tempdir().unwrap();
+    let mut data = Vec::new();
+    for i in 0..2_000_000 {
+        let line = format!(
+            "192.168.{}.{} - - [01/Jan/2024:00:00:00 +0000] \"GET /index.html HTTP/1.1\" 200 1234 \"-\" \"Mozilla/5.0\"\n",
+            (i / 256) % 256,
+            i % 256
+        );
+        data.extend_from_slice(line.as_bytes());
+    }
+    let file_path = create_test_file(&data, temp_dir.path());
+    let file_path_str = file_path.to_str().unwrap();
+
+    bencher.bench(|| {
+        black_box(run_util_function(
+            uumain,
+            &["athe-line-ends-here", file_path_str],
+        ));
+    });
+}
+
+/// Benchmark remove carriage return
+#[divan::bench]
+fn remove_cr(bencher: Bencher) {
+    let temp_dir = tempfile::tempdir().unwrap();
+    let mut data = Vec::new();
+    for i in 0..500_000 {
+        let line = format!("line {} with windows endings\r\n", i);
+        data.extend_from_slice(line.as_bytes());
+    }
+    let file_path = create_test_file(&data, temp_dir.path());
+    let file_path_str = file_path.to_str().unwrap();
+
+    bencher.bench(|| {
+        black_box(run_util_function(uumain, &["s/\r$//", file_path_str]));
+    });
+}
+
+/// Benchmark genomic data substitution
+#[divan::bench]
+fn genome_subst(bencher: Bencher) {
+    let temp_dir = tempfile::tempdir().unwrap();
+    let mut data = Vec::new();
+    for i in 0..100_000 {
+        let chr = format!("chr{}", 1 + i % 22);
+        let line = format!(
+            "{}\t{}\t{}\t.\t{}\t.\t.\n",
+            chr,
+            i * 100,
+            if i % 2 == 1 { "A" } else { "T" },
+            if i % 2 == 1 { "G" } else { "C" }
+        );
+        data.extend_from_slice(line.as_bytes());
+    }
+    let file_path = create_test_file(&data, temp_dir.path());
+    let file_path_str = file_path.to_str().unwrap();
+
+    bencher.bench(|| {
+        black_box(run_util_function(
+            uumain,
+            &["/^#/d; s/\t\\./\tNA/g; s/\\.$/NA/", file_path_str],
+        ));
+    });
+}
+
+/// Benchmark number formatting
+#[divan::bench]
+fn number_fix(bencher: Bencher) {
+    let temp_dir = tempfile::tempdir().unwrap();
+    let mut data = Vec::new();
+    for i in 0..100_000 {
+        let euros = i % 10000;
+        let cents = i % 100;
+        let thousands = euros / 1000;
+        let remainder = euros % 1000;
+        let line = format!("{}.{:03},{:02}\n", thousands, remainder, cents);
+        data.extend_from_slice(line.as_bytes());
+    }
+    let file_path = create_test_file(&data, temp_dir.path());
+    let file_path_str = file_path.to_str().unwrap();
+
+    bencher.bench(|| {
+        black_box(run_util_function(
+            uumain,
+            &[
+                "s/\\([0-9]\\)\\.\\([0-9]\\)/\\1\\2/g;s/\\([0-9]\\),\\([0-9]\\)/\\1.\\2/g",
+                file_path_str,
+            ],
+        ));
+    });
+}
+
+fn main() {
+    divan::main();
+}