diff --git a/bench/base64-decode-perf.scm b/bench/base64-decode-perf.scm
new file mode 100644
index 00000000..433075c0
--- /dev/null
+++ b/bench/base64-decode-perf.scm
@@ -0,0 +1,79 @@
+;;
+;; Copyright (C) 2026 The Goldfish Scheme Authors
+;;
+;; Licensed under the Apache License, Version 2.0 (the "License");
+;; you may not use this file except in compliance with the License.
+;; You may obtain a copy of the License at
+;;
+;; http://www.apache.org/licenses-2.0
+;;
+;; Unless required by applicable law or agreed to in writing, software
+;; distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+;; WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+;; License for the specific language governing permissions and limitations
+;; under the License.
+;;
+
+;; base64-decode 性能基准：仅测统一入口 base64-decode（按参数类型分发到 string / bytevector）
+
+(import (liii base) (liii base64) (liii timeit))
+
+(define (build-ascii-string n)
+  (let ((out (open-output-string)))
+    (do ((i 0 (+ i 1)))
+      ((= i n))
+      (display (integer->char (+ 97 (modulo i 26))) out)
+    ) ;do
+    (get-output-string out)
+  ) ;let
+) ;define
+
+(define (build-binary-bv n)
+  (let ((bv (make-bytevector n)))
+    (do ((i 0 (+ i 1)))
+      ((= i n))
+      (bytevector-u8-set! bv i (modulo (* i 31) 256))
+    ) ;do
+    bv
+  ) ;let
+) ;define
+
+(define medium-n 1024)
+
+(define ascii-medium (build-ascii-string medium-n))
+
+(define bv-medium (build-binary-bv medium-n))
+
+(define enc-ascii-medium (string-base64-encode ascii-medium))
+
+(define enc-bv-medium (bytevector-base64-encode bv-medium))
+
+(define iter 15)
+
+(define (report title iterations time-val)
+  (display "[")
+  (display title)
+  (display "] iterations=")
+  (display iterations)
+  (display " time=")
+  (display time-val)
+  (display "s")
+  (newline)
+) ;define
+
+(do ((i 0 (+ i 1)))
+  ((= i 5))
+  (base64-decode enc-ascii-medium)
+  (base64-decode enc-bv-medium)
+) ;do
+
+(display "=== base64-decode 性能基准测试 ===")
+(newline)
+(newline)
+
+(let ((t (timeit (lambda () (base64-decode enc-ascii-medium)) '() iter)))
+  (report "base64-decode string(1KB)" iter t)
+) ;let
+(let ((t (timeit (lambda () (base64-decode enc-bv-medium)) '() iter)))
+  (report "base64-decode bytevector(1KB)" iter t)
+) ;let
diff --git a/bench/base64-encode-perf.scm b/bench/base64-encode-perf.scm
new file mode 100644
index 00000000..d166787e
--- /dev/null
+++ b/bench/base64-encode-perf.scm
@@ -0,0 +1,75 @@
+;;
+;; Copyright (C) 2026 The Goldfish Scheme Authors
+;;
+;; Licensed under the Apache License, Version 2.0 (the "License");
+;; you may not use this file except in compliance with the License.
+;; You may obtain a copy of the License at
+;;
+;; http://www.apache.org/licenses-2.0
+;;
+;; Unless required by applicable law or agreed to in writing, software
+;; distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+;; WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+;; License for the specific language governing permissions and limitations
+;; under the License.
+;;
+
+;; base64-encode 性能基准：仅测统一入口 base64-encode（按参数类型分发到 string / bytevector）
+
+(import (liii base) (liii base64) (liii timeit))
+
+(define (build-ascii-string n)
+  (let ((out (open-output-string)))
+    (do ((i 0 (+ i 1)))
+      ((= i n))
+      (display (integer->char (+ 97 (modulo i 26))) out)
+    ) ;do
+    (get-output-string out)
+  ) ;let
+) ;define
+
+(define (build-binary-bv n)
+  (let ((bv (make-bytevector n)))
+    (do ((i 0 (+ i 1)))
+      ((= i n))
+      (bytevector-u8-set! bv i (modulo (* i 31) 256))
+    ) ;do
+    bv
+  ) ;let
+) ;define
+
+(define medium-n 1024)
+
+(define ascii-medium (build-ascii-string medium-n))
+
+(define bv-medium (build-binary-bv medium-n))
+
+(define iter 30)
+
+(define (report title iterations time-val)
+  (display "[")
+  (display title)
+  (display "] iterations=")
+  (display iterations)
+  (display " time=")
+  (display time-val)
+  (display "s")
+  (newline)
+) ;define
+
+(do ((i 0 (+ i 1)))
+  ((= i 5))
+  (base64-encode ascii-medium)
+  (base64-encode bv-medium)
+) ;do
+
+(display "=== base64-encode 性能基准测试 ===")
+(newline)
+(newline)
+
+(let ((t (timeit (lambda () (base64-encode ascii-medium)) '() iter)))
+  (report "base64-encode string(1KB)" iter t)
+) ;let
+(let ((t (timeit (lambda () (base64-encode bv-medium)) '() iter)))
+  (report "base64-encode bytevector(1KB)" iter t)
+) ;let
diff --git a/bench/base64-perf.scm b/bench/base64-perf.scm
deleted file mode 100644
index b0dda1e8..00000000
--- a/bench/base64-perf.scm
+++ /dev/null
@@ -1,271 +0,0 @@
-;;
-;; Copyright (C) 2026 The Goldfish Scheme Authors
-;;
-;; Licensed under the Apache License, Version 2.0 (the "License");
-;; you may not use this file except in compliance with the License.
-;; You may obtain a copy of the License at
-;;
-;; http://www.apache.org/LICENSE-2.0
-;;
-;; Unless required by applicable law or agreed to in writing, software
-;; distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
-;; WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
-;; License for the specific language governing permissions and limitations
-;; under the License.
-;;
-
-(import (liii base) (liii base64) (liii timeit))
-
-(define (build-ascii-string n)
-  (let ((out (open-output-string)))
-    (do ((i 0 (+ i 1)))
-      ((= i n))
-      (display (integer->char (+ 97 (modulo i 26))) out)
-    ) ;do
-    (get-output-string out)
-  ) ;let
-) ;define
-
-(define (build-binary-bv n)
-  (let ((bv (make-bytevector n)))
-    (do ((i 0 (+ i 1)))
-      ((= i n))
-      (bytevector-u8-set! bv i (modulo (* i 31) 256))
-    ) ;do
-    bv
-  ) ;let
-) ;define
-
-(define tiny-n 8)
-
-(define small-n 100)
-
-(define medium-n 1024)
-
-(define large-n (* 10 1024))
-
-(define ascii-tiny (build-ascii-string tiny-n))
-
-(define ascii-small (build-ascii-string small-n))
-
-(define ascii-medium (build-ascii-string medium-n))
-
-(define ascii-large (build-ascii-string large-n))
-
-(define bv-tiny (build-binary-bv tiny-n))
-
-(define bv-small (build-binary-bv small-n))
-
-(define bv-medium (build-binary-bv medium-n))
-
-(define bv-large (build-binary-bv large-n))
-
-(define enc-ascii-tiny (string-base64-encode ascii-tiny))
-
-(define enc-ascii-small (string-base64-encode ascii-small))
-
-(define enc-ascii-medium (string-base64-encode ascii-medium))
-
-(define enc-ascii-large (string-base64-encode ascii-large))
-
-(define enc-bv-tiny (bytevector-base64-encode bv-tiny))
-
-(define enc-bv-small (bytevector-base64-encode bv-small))
-
-(define enc-bv-medium (bytevector-base64-encode bv-medium))
-
-(define enc-bv-large (bytevector-base64-encode bv-large))
-
-(define (report title iterations time-val)
-  (display "[")
-  (display title)
-  (display "] iterations=")
-  (display iterations)
-  (display " time=")
-  (display time-val)
-  (display "s")
-  (newline)
-) ;define
-
-(do ((i 0 (+ i 1)))
-  ((= i 5))
-  (string-base64-encode ascii-small)
-  (string-base64-decode enc-ascii-small)
-  (bytevector-base64-encode bv-small)
-  (bytevector-base64-decode enc-bv-small)
-) ;do
-
-(define str-enc-tiny-iter 3000)
-
-(define str-enc-small-iter 300)
-
-(define str-enc-medium-iter 30)
-
-(define str-enc-large-iter 3)
-
-(define str-decode-tiny-iter 1500)
-
-(define str-decode-small-iter 150)
-
-(define str-decode-medium-iter 15)
-
-(define str-decode-large-iter 2)
-
-(define bv-enc-tiny-iter 3000)
-
-(define bv-enc-small-iter 300)
-
-(define bv-enc-medium-iter 30)
-
-(define bv-enc-large-iter 3)
-
-(define bv-decode-tiny-iter 1500)
-
-(define bv-decode-small-iter 150)
-
-(define bv-decode-medium-iter 15)
-
-(define bv-decode-large-iter 2)
-
-(define unified-enc-iter 30)
-
-(define unified-decode-iter 15)
-
-(display "=== (liii base64) 性能基准测试 ===")
-(newline)
-(newline)
-
-(display "--- string-base64-encode ---")
-(newline)
-(let ((t (timeit (lambda () (string-base64-encode ascii-tiny)) '() str-enc-tiny-iter))
-     ) ;
-  (report "string-base64-encode tiny(8B)" str-enc-tiny-iter t)
-) ;let
-(let ((t (timeit (lambda () (string-base64-encode ascii-small)) '() str-enc-small-iter)
-      ) ;t
-     ) ;
-  (report "string-base64-encode small(100B)" str-enc-small-iter t)
-) ;let
-(let ((t (timeit (lambda () (string-base64-encode ascii-medium)) '() str-enc-medium-iter)
-      ) ;t
-     ) ;
-  (report "string-base64-encode medium(1KB)" str-enc-medium-iter t)
-) ;let
-(let ((t (timeit (lambda () (string-base64-encode ascii-large)) '() str-enc-large-iter)
-      ) ;t
-     ) ;
-  (report "string-base64-encode large(10KB)" str-enc-large-iter t)
-) ;let
-(newline)
-
-(display "--- string-base64-decode ---")
-(newline)
-(let ((t (timeit (lambda () (string-base64-decode enc-ascii-tiny))
-           '()
-           str-decode-tiny-iter
-         ) ;timeit
-      ) ;t
-     ) ;
-  (report "string-base64-decode tiny(8B)" str-decode-tiny-iter t)
-) ;let
-(let ((t (timeit (lambda () (string-base64-decode enc-ascii-small))
-           '()
-           str-decode-small-iter
-         ) ;timeit
-      ) ;t
-     ) ;
-  (report "string-base64-decode small(100B)" str-decode-small-iter t)
-) ;let
-(let ((t (timeit (lambda () (string-base64-decode enc-ascii-medium))
-           '()
-           str-decode-medium-iter
-         ) ;timeit
-      ) ;t
-     ) ;
-  (report "string-base64-decode medium(1KB)" str-decode-medium-iter t)
-) ;let
-(let ((t (timeit (lambda () (string-base64-decode enc-ascii-large))
-           '()
-           str-decode-large-iter
-         ) ;timeit
-      ) ;t
-     ) ;
-  (report "string-base64-decode large(10KB)" str-decode-large-iter t)
-) ;let
-(newline)
-
-(display "--- bytevector-base64-encode ---")
-(newline)
-(let ((t (timeit (lambda () (bytevector-base64-encode bv-tiny)) '() bv-enc-tiny-iter))
-     ) ;
-  (report "bytevector-base64-encode tiny(8B)" bv-enc-tiny-iter t)
-) ;let
-(let ((t (timeit (lambda () (bytevector-base64-encode bv-small)) '() bv-enc-small-iter)
-      ) ;t
-     ) ;
-  (report "bytevector-base64-encode small(100B)" bv-enc-small-iter t)
-) ;let
-(let ((t (timeit (lambda () (bytevector-base64-encode bv-medium)) '() bv-enc-medium-iter)
-      ) ;t
-     ) ;
-  (report "bytevector-base64-encode medium(1KB)" bv-enc-medium-iter t)
-) ;let
-(let ((t (timeit (lambda () (bytevector-base64-encode bv-large)) '() bv-enc-large-iter)
-      ) ;t
-     ) ;
-  (report "bytevector-base64-encode large(10KB)" bv-enc-large-iter t)
-) ;let
-(newline)
-
-(display "--- bytevector-base64-decode ---")
-(newline)
-(let ((t (timeit (lambda () (bytevector-base64-decode enc-bv-tiny))
-           '()
-           bv-decode-tiny-iter
-         ) ;timeit
-      ) ;t
-     ) ;
-  (report "bytevector-base64-decode tiny(8B)" bv-decode-tiny-iter t)
-) ;let
-(let ((t (timeit (lambda () (bytevector-base64-decode enc-bv-small))
-           '()
-           bv-decode-small-iter
-         ) ;timeit
-      ) ;t
-     ) ;
-  (report "bytevector-base64-decode small(100B)" bv-decode-small-iter t)
-) ;let
-(let ((t (timeit (lambda () (bytevector-base64-decode enc-bv-medium))
-           '()
-           bv-decode-medium-iter
-         ) ;timeit
-      ) ;t
-     ) ;
-  (report "bytevector-base64-decode medium(1KB)" bv-decode-medium-iter t)
-) ;let
-(let ((t (timeit (lambda () (bytevector-base64-decode enc-bv-large))
-           '()
-           bv-decode-large-iter
-         ) ;timeit
-      ) ;t
-     ) ;
-  (report "bytevector-base64-decode large(10KB)" bv-decode-large-iter t)
-) ;let
-(newline)
-
-(display "--- base64-encode / base64-decode 统一入口 ---")
-(newline)
-(let ((t (timeit (lambda () (base64-encode ascii-medium)) '() unified-enc-iter)))
-  (report "base64-encode string(1KB)" unified-enc-iter t)
-) ;let
-(let ((t (timeit (lambda () (base64-encode bv-medium)) '() unified-enc-iter)))
-  (report "base64-encode bytevector(1KB)" unified-enc-iter t)
-) ;let
-(let ((t (timeit (lambda () (base64-decode enc-ascii-medium)) '() unified-decode-iter)
-      ) ;t
-     ) ;
-  (report "base64-decode string(1KB)" unified-decode-iter t)
-) ;let
-(let ((t (timeit (lambda () (base64-decode enc-bv-medium)) '() unified-decode-iter)))
-  (report "base64-decode bytevector(1KB)" unified-decode-iter t)
-) ;let
diff --git a/bench/bytevector-base64-decode-perf.scm b/bench/bytevector-base64-decode-perf.scm
new file mode 100644
index 00000000..d86110e5
--- /dev/null
+++ b/bench/bytevector-base64-decode-perf.scm
@@ -0,0 +1,94 @@
+;;
+;; Copyright (C) 2026 The Goldfish Scheme Authors
+;;
+;; Licensed under the Apache License, Version 2.0 (the "License");
+;; you may not use this file except in compliance with the License.
+;; You may obtain a copy of the License at
+;;
+;; http://www.apache.org/licenses-2.0
+;;
+;; Unless required by applicable law or agreed to in writing, software
+;; distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+;; WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+;; License for the specific language governing permissions and limitations
+;; under the License.
+;;
+
+;; bytevector-base64-decode 性能基准：仅测 bytevector-base64-decode 一个函数
+
+(import (liii base) (liii base64) (liii timeit))
+
+(define (build-binary-bv n)
+  (let ((bv (make-bytevector n)))
+    (do ((i 0 (+ i 1)))
+      ((= i n))
+      (bytevector-u8-set! bv i (modulo (* i 31) 256))
+    ) ;do
+    bv
+  ) ;let
+) ;define
+
+(define tiny-n 8)
+
+(define small-n 100)
+
+(define medium-n 1024)
+
+(define large-n (* 10 1024))
+
+(define bv-tiny (build-binary-bv tiny-n))
+
+(define bv-small (build-binary-bv small-n))
+
+(define bv-medium (build-binary-bv medium-n))
+
+(define bv-large (build-binary-bv large-n))
+
+(define enc-tiny (bytevector-base64-encode bv-tiny))
+
+(define enc-small (bytevector-base64-encode bv-small))
+
+(define enc-medium (bytevector-base64-encode bv-medium))
+
+(define enc-large (bytevector-base64-encode bv-large))
+
+(define tiny-iter 1500)
+
+(define small-iter 150)
+
+(define medium-iter 15)
+
+(define large-iter 2)
+
+(define (report title iterations time-val)
+  (display "[")
+  (display title)
+  (display "] iterations=")
+  (display iterations)
+  (display " time=")
+  (display time-val)
+  (display "s")
+  (newline)
+) ;define
+
+(do ((i 0 (+ i 1)))
+  ((= i 5))
+  (bytevector-base64-decode enc-small)
+) ;do
+
+(display "=== bytevector-base64-decode 性能基准测试 ===")
+(newline)
+(newline)
+
+(let ((t (timeit (lambda () (bytevector-base64-decode enc-tiny)) '() tiny-iter)))
+  (report "bytevector-base64-decode tiny(8B)" tiny-iter t)
+) ;let
+(let ((t (timeit (lambda () (bytevector-base64-decode enc-small)) '() small-iter)))
+  (report "bytevector-base64-decode small(100B)" small-iter t)
+) ;let
+(let ((t (timeit (lambda () (bytevector-base64-decode enc-medium)) '() medium-iter)))
+  (report "bytevector-base64-decode medium(1KB)" medium-iter t)
+) ;let
+(let ((t (timeit (lambda () (bytevector-base64-decode enc-large)) '() large-iter)))
+  (report "bytevector-base64-decode large(10KB)" large-iter t)
+) ;let
diff --git a/bench/bytevector-base64-encode-perf.scm b/bench/bytevector-base64-encode-perf.scm
new file mode 100644
index 00000000..f2a40b5c
--- /dev/null
+++ b/bench/bytevector-base64-encode-perf.scm
@@ -0,0 +1,86 @@
+;;
+;; Copyright (C) 2026 The Goldfish Scheme Authors
+;;
+;; Licensed under the Apache License, Version 2.0 (the "License");
+;; you may not use this file except in compliance with the License.
+;; You may obtain a copy of the License at
+;;
+;; http://www.apache.org/licenses-2.0
+;;
+;; Unless required by applicable law or agreed to in writing, software
+;; distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+;; WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+;; License for the specific language governing permissions and limitations
+;; under the License.
+;;
+
+;; bytevector-base64-encode 性能基准：仅测 bytevector-base64-encode 一个函数
+
+(import (liii base) (liii base64) (liii timeit))
+
+(define (build-binary-bv n)
+  (let ((bv (make-bytevector n)))
+    (do ((i 0 (+ i 1)))
+      ((= i n))
+      (bytevector-u8-set! bv i (modulo (* i 31) 256))
+    ) ;do
+    bv
+  ) ;let
+) ;define
+
+(define tiny-n 8)
+
+(define small-n 100)
+
+(define medium-n 1024)
+
+(define large-n (* 10 1024))
+
+(define bv-tiny (build-binary-bv tiny-n))
+
+(define bv-small (build-binary-bv small-n))
+
+(define bv-medium (build-binary-bv medium-n))
+
+(define bv-large (build-binary-bv large-n))
+
+(define tiny-iter 3000)
+
+(define small-iter 300)
+
+(define medium-iter 30)
+
+(define large-iter 3)
+
+(define (report title iterations time-val)
+  (display "[")
+  (display title)
+  (display "] iterations=")
+  (display iterations)
+  (display " time=")
+  (display time-val)
+  (display "s")
+  (newline)
+) ;define
+
+(do ((i 0 (+ i 1)))
+  ((= i 5))
+  (bytevector-base64-encode bv-small)
+) ;do
+
+(display "=== bytevector-base64-encode 性能基准测试 ===")
+(newline)
+(newline)
+
+(let ((t (timeit (lambda () (bytevector-base64-encode bv-tiny)) '() tiny-iter)))
+  (report "bytevector-base64-encode tiny(8B)" tiny-iter t)
+) ;let
+(let ((t (timeit (lambda () (bytevector-base64-encode bv-small)) '() small-iter)))
+  (report "bytevector-base64-encode small(100B)" small-iter t)
+) ;let
+(let ((t (timeit (lambda () (bytevector-base64-encode bv-medium)) '() medium-iter)))
+  (report "bytevector-base64-encode medium(1KB)" medium-iter t)
+) ;let
+(let ((t (timeit (lambda () (bytevector-base64-encode bv-large)) '() large-iter)))
+  (report "bytevector-base64-encode large(10KB)" large-iter t)
+) ;let
diff --git a/bench/string-base64-decode-perf.scm b/bench/string-base64-decode-perf.scm
new file mode 100644
index 00000000..5c5ac791
--- /dev/null
+++ b/bench/string-base64-decode-perf.scm
@@ -0,0 +1,94 @@
+;;
+;; Copyright (C) 2026 The Goldfish Scheme Authors
+;;
+;; Licensed under the Apache License, Version 2.0 (the "License");
+;; you may not use this file except in compliance with the License.
+;; You may obtain a copy of the License at
+;;
+;; http://www.apache.org/licenses-2.0
+;;
+;; Unless required by applicable law or agreed to in writing, software
+;; distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+;; WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+;; License for the specific language governing permissions and limitations
+;; under the License.
+;;
+
+;; string-base64-decode 性能基准：仅测 string-base64-decode 一个函数
+
+(import (liii base) (liii base64) (liii timeit))
+
+(define (build-ascii-string n)
+  (let ((out (open-output-string)))
+    (do ((i 0 (+ i 1)))
+      ((= i n))
+      (display (integer->char (+ 97 (modulo i 26))) out)
+    ) ;do
+    (get-output-string out)
+  ) ;let
+) ;define
+
+(define tiny-n 8)
+
+(define small-n 100)
+
+(define medium-n 1024)
+
+(define large-n (* 10 1024))
+
+(define ascii-tiny (build-ascii-string tiny-n))
+
+(define ascii-small (build-ascii-string small-n))
+
+(define ascii-medium (build-ascii-string medium-n))
+
+(define ascii-large (build-ascii-string large-n))
+
+(define enc-tiny (string-base64-encode ascii-tiny))
+
+(define enc-small (string-base64-encode ascii-small))
+
+(define enc-medium (string-base64-encode ascii-medium))
+
+(define enc-large (string-base64-encode ascii-large))
+
+(define tiny-iter 1500)
+
+(define small-iter 150)
+
+(define medium-iter 15)
+
+(define large-iter 2)
+
+(define (report title iterations time-val)
+  (display "[")
+  (display title)
+  (display "] iterations=")
+  (display iterations)
+  (display " time=")
+  (display time-val)
+  (display "s")
+  (newline)
+) ;define
+
+(do ((i 0 (+ i 1)))
+  ((= i 5))
+  (string-base64-decode enc-small)
+) ;do
+
+(display "=== string-base64-decode 性能基准测试 ===")
+(newline)
+(newline)
+
+(let ((t (timeit (lambda () (string-base64-decode enc-tiny)) '() tiny-iter)))
+  (report "string-base64-decode tiny(8B)" tiny-iter t)
+) ;let
+(let ((t (timeit (lambda () (string-base64-decode enc-small)) '() small-iter)))
+  (report "string-base64-decode small(100B)" small-iter t)
+) ;let
+(let ((t (timeit (lambda () (string-base64-decode enc-medium)) '() medium-iter)))
+  (report "string-base64-decode medium(1KB)" medium-iter t)
+) ;let
+(let ((t (timeit (lambda () (string-base64-decode enc-large)) '() large-iter)))
+  (report "string-base64-decode large(10KB)" large-iter t)
+) ;let
diff --git a/bench/string-base64-encode-perf.scm b/bench/string-base64-encode-perf.scm
new file mode 100644
index 00000000..54596600
--- /dev/null
+++ b/bench/string-base64-encode-perf.scm
@@ -0,0 +1,86 @@
+;;
+;; Copyright (C) 2026 The Goldfish Scheme Authors
+;;
+;; Licensed under the Apache License, Version 2.0 (the "License");
+;; you may not use this file except in compliance with the License.
+;; You may obtain a copy of the License at
+;;
+;; http://www.apache.org/licenses-2.0
+;;
+;; Unless required by applicable law or agreed to in writing, software
+;; distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+;; WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+;; License for the specific language governing permissions and limitations
+;; under the License.
+;;
+
+;; string-base64-encode 性能基准：仅测 string-base64-encode 一个函数
+
+(import (liii base) (liii base64) (liii timeit))
+
+(define (build-ascii-string n)
+  (let ((out (open-output-string)))
+    (do ((i 0 (+ i 1)))
+      ((= i n))
+      (display (integer->char (+ 97 (modulo i 26))) out)
+    ) ;do
+    (get-output-string out)
+  ) ;let
+) ;define
+
+(define tiny-n 8)
+
+(define small-n 100)
+
+(define medium-n 1024)
+
+(define large-n (* 10 1024))
+
+(define ascii-tiny (build-ascii-string tiny-n))
+
+(define ascii-small (build-ascii-string small-n))
+
+(define ascii-medium (build-ascii-string medium-n))
+
+(define ascii-large (build-ascii-string large-n))
+
+(define tiny-iter 3000)
+
+(define small-iter 300)
+
+(define medium-iter 30)
+
+(define large-iter 3)
+
+(define (report title iterations time-val)
+  (display "[")
+  (display title)
+  (display "] iterations=")
+  (display iterations)
+  (display " time=")
+  (display time-val)
+  (display "s")
+  (newline)
+) ;define
+
+(do ((i 0 (+ i 1)))
+  ((= i 5))
+  (string-base64-encode ascii-small)
+) ;do
+
+(display "=== string-base64-encode 性能基准测试 ===")
+(newline)
+(newline)
+
+(let ((t (timeit (lambda () (string-base64-encode ascii-tiny)) '() tiny-iter)))
+  (report "string-base64-encode tiny(8B)" tiny-iter t)
+) ;let
+(let ((t (timeit (lambda () (string-base64-encode ascii-small)) '() small-iter)))
+  (report "string-base64-encode small(100B)" small-iter t)
+) ;let
+(let ((t (timeit (lambda () (string-base64-encode ascii-medium)) '() medium-iter)))
+  (report "string-base64-encode medium(1KB)" medium-iter t)
+) ;let
+(let ((t (timeit (lambda () (string-base64-encode ascii-large)) '() large-iter)))
+  (report "string-base64-encode large(10KB)" large-iter t)
+) ;let
diff --git a/devel/0081.md b/devel/0081.md
new file mode 100644
index 00000000..0e2995ac
--- /dev/null
+++ b/devel/0081.md
@@ -0,0 +1,67 @@
+# [0081] base64 单元测试与 perf 拆分
+
+## 任务相关的代码文件
+- tests/liii/base64/bytevector-base64-encode-test.scm （新增）
+- goldfish/liii/base64.scm （被测实现，未改动）
+- bench/base64-perf.scm （删除）
+- bench/string-base64-encode-perf.scm （新增）
+- bench/string-base64-decode-perf.scm （新增）
+- bench/bytevector-base64-encode-perf.scm （新增）
+- bench/bytevector-base64-decode-perf.scm （新增）
+- bench/base64-encode-perf.scm （新增）
+- bench/base64-decode-perf.scm （新增）
+
+## 如何测试
+```
+xmake config --yes
+xmake b goldfish
+bin/gf fmt tests/liii/base64/bytevector-base64-encode-test.scm
+bin/gf tests/liii/base64/bytevector-base64-encode-test.scm
+bin/gf tests/liii/base64/bytevector-base64-decode-test.scm
+bin/gf tests/liii/base64/base64-encode-test.scm
+bin/gf tests/liii/base64/base64-decode-test.scm
+bin/gf bench/string-base64-encode-perf.scm
+bin/gf bench/string-base64-decode-perf.scm
+bin/gf bench/bytevector-base64-encode-perf.scm
+bin/gf bench/bytevector-base64-decode-perf.scm
+bin/gf bench/base64-encode-perf.scm
+bin/gf bench/base64-decode-perf.scm
+```
+
+## 2026/06/28 base64 性能基准拆分到以函数为单位
+### What
+把原 `bench/base64-perf.scm`（一个文件混测 6 个函数）拆成 6 个以函数为单位的独立 bench 文件，每个文件自包含辅助函数、数据构建、各档迭代次数，可独立运行。
+
+1. 新增 `bench/string-base64-encode-perf.scm`：仅测 `string-base64-encode`，tiny/small/medium/large 四档
+2. 新增 `bench/string-base64-decode-perf.scm`：仅测 `string-base64-decode`，tiny/small/medium/large 四档
+3. 新增 `bench/bytevector-base64-encode-perf.scm`：仅测 `bytevector-base64-encode`，tiny/small/medium/large 四档
+4. 新增 `bench/bytevector-base64-decode-perf.scm`：仅测 `bytevector-base64-decode`，tiny/small/medium/large 四档
+5. 新增 `bench/base64-encode-perf.scm`：仅测统一入口 `base64-encode`，medium 一档（string + bytevector）
+6. 新增 `bench/base64-decode-perf.scm`：仅测统一入口 `base64-decode`，medium 一档（string + bytevector）
+7. 删除原 `bench/base64-perf.scm`
+
+### Why
+原 `bench/base64-perf.scm` 把 6 个函数塞在同一个文件里：定位某个函数的耗时需要在长输出里翻找，单独重测某个函数要跑整套（debug 构建下约 9s），且后续 `bytevector-base64-encode` 下沉到 native 时（见后续任务）只想盯单函数的 before/after 对比，混测文件不便于做这种聚焦回归。拆成以函数为单位后，单函数 perf 可独立运行、独立对比。
+
+### How
+- 每个文件沿用原文件的迭代次数档位（encode 系 tiny=3000/small=300/medium=30/large=3；decode 系减半；统一入口 medium=30 或 15）
+- 每个文件自带 `build-ascii-string` / `build-binary-bv` 与对应规模数据，避免相互依赖
+- decode 类 bench 在文件内先用对应 encode 函数生成 `enc-*` 数据，再进入计时
+- 统一入口 `base64-encode` / `base64-decode` 只测 medium 一档（它们只是按参数类型转发到上面 4 个函数）
+
+## 2026/06/28 为 bytevector-base64-encode 新增单元测试
+### What
+仿照 [0079](0079.md) 为 `bytevector-base64-decode` 单独建立测试文件的做法，为 `bytevector-base64-encode` 新建 `tests/liii/base64/bytevector-base64-encode-test.scm`，共 22 个 check，作为后续把 encode 也下沉到 native C++ 的回归基线。
+
+1. 新增 `tests/liii/base64/bytevector-base64-encode-test.scm`，覆盖空输入、RFC 4648 标准示例（1~6 字节，覆盖 `==` / `=` / 无填充三种模式）、边界字节（0 / 255 / NUL 不被截断）、字符集 `+/3+`、较长输入、round-trip 一致性、类型错误
+
+### Why
+[0080](0080.md) 已把 decode 下沉到 native，性能瓶颈随之转移到 encode 路径（large(10KB) 单次约 220ms，详见 [0080](0080.md) 性能对比表）。在动手下沉 encode 之前，先按 TDD 思路固定语义契约，避免下沉过程中破坏现有行为。`bytevector-base64-encode` 当前实现（`goldfish/liii/base64.scm` 第 18~62 行）使用 `BYTE2BASE64_BV` 查表，输出是 bytevector 而非 string，因此期望值统一用 `string->utf8` 包装，与 decode 测试文件保持对称。
+
+### How
+- 测试结构与 `bytevector-base64-decode-test.scm` 完全对称，便于阅读和维护
+- round-trip 部分直接复用已下沉到 native 的 `bytevector-base64-decode`，两端互为交叉校验
+- 类型错误用 `check-catch 'type-error`，覆盖 string / 整数 / symbol 三种典型非 bytevector 输入
+
+## 后续任务（暂不在本 PR 完成）
+- 把 `bytevector-base64-encode` 下沉到 native C++，进一步压低 large(10KB) 的 220ms 量级（与 [0080](0080.md) decode 下沉思路一致）
diff --git a/tests/liii/base64/bytevector-base64-encode-test.scm b/tests/liii/base64/bytevector-base64-encode-test.scm
new file mode 100644
index 00000000..930cef9c
--- /dev/null
+++ b/tests/liii/base64/bytevector-base64-encode-test.scm
@@ -0,0 +1,92 @@
+(import (liii base64) (liii check))
+
+(check-set-mode! 'report-failed)
+
+;; bytevector-base64-encode
+;; 将原始字节向量编码为 Base64 字节向量。
+;;
+;; 语法
+;; ----
+;; (bytevector-base64-encode bv)
+;;
+;; 参数
+;; ----
+;; bv : bytevector
+;; 要编码的原始字节序列。
+;;
+;; 返回值
+;; ----
+;; bytevector
+;; Base64 编码后的字节向量，遵循 RFC 4648：
+;; - 每 3 个字节编码为 4 个字符
+;; - 不足 3 字节时使用 '=' 填充
+;; - 字符集为 A-Z, a-z, 0-9, '+', '/'
+;; - 输出长度恒为 4 的倍数
+;;
+;; 注意
+;; ----
+;; - 空字节向量编码为空字节向量
+;; - 输出字节值为 ASCII（0~127），不做 UTF-8 转换
+;;
+;; 错误处理
+;; ----
+;; - 输入非 bytevector -> type-error
+
+;; 空输入
+(check (bytevector-base64-encode #u8()) => #u8())
+
+;; 标准 RFC 4648 示例（覆盖 1/2/3 字节填充情况）
+(check (bytevector-base64-encode #u8(102)) => (string->utf8 "Zg=="))
+(check (bytevector-base64-encode #u8(102 111)) => (string->utf8 "Zm8="))
+(check (bytevector-base64-encode #u8(102 111 111)) => (string->utf8 "Zm9v"))
+(check (bytevector-base64-encode #u8(102 111 111 98))
+  =>
+  (string->utf8 "Zm9vYg==")
+) ;check
+(check (bytevector-base64-encode #u8(102 111 111 98 97))
+  =>
+  (string->utf8 "Zm9vYmE=")
+) ;check
+(check (bytevector-base64-encode #u8(102 111 111 98 97 114))
+  =>
+  (string->utf8 "Zm9vYmFy")
+) ;check
+
+;; 边界字节（覆盖全部填充情况）
+(check (bytevector-base64-encode #u8(0)) => (string->utf8 "AA=="))
+(check (bytevector-base64-encode #u8(255)) => (string->utf8 "/w=="))
+(check (bytevector-base64-encode #u8(0 0)) => (string->utf8 "AAA="))
+(check (bytevector-base64-encode #u8(255 255)) => (string->utf8 "//8="))
+(check (bytevector-base64-encode #u8(0 0 0)) => (string->utf8 "AAAA"))
+(check (bytevector-base64-encode #u8(255 255 255)) => (string->utf8 "////"))
+
+;; 字符集覆盖（+ / 边界）
+(check (bytevector-base64-encode #u8(251 253 254)) => (string->utf8 "+/3+"))
+
+;; 含 NUL 字节（不应被截断）
+(check (bytevector-base64-encode #u8(0 0 0)) => (string->utf8 "AAAA"))
+
+;; 较长输入
+(check (bytevector-base64-encode (string->utf8 "The quick brown fox jumps over the lazy dog.")
+       ) ;bytevector-base64-encode
+  =>
+  (string->utf8 "VGhlIHF1aWNrIGJyb3duIGZveCBqdW1wcyBvdmVyIHRoZSBsYXp5IGRvZy4=")
+) ;check
+
+;; Round-trip 一致性
+(check (bytevector-base64-decode (bytevector-base64-encode #u8())) => #u8())
+(check (bytevector-base64-decode (bytevector-base64-encode #u8(1 2 3 4 5)))
+  =>
+  #u8(1 2 3 4 5)
+) ;check
+(check (bytevector-base64-decode (bytevector-base64-encode #u8(255 0 127 128)))
+  =>
+  #u8(255 0 127 128)
+) ;check
+
+;; 类型错误
+(check-catch 'type-error (bytevector-base64-encode "foo"))
+(check-catch 'type-error (bytevector-base64-encode 123))
+(check-catch 'type-error (bytevector-base64-encode 'sym))
+
+(check-report)