diff --git a/README.en.md b/README.en.md
index 5e1d427..e92edae 100644
--- a/README.en.md
+++ b/README.en.md
@@ -42,6 +42,16 @@ Server-side subsetting + client-side incremental loading.
 6 characters → server subsets font → returns ~6KB (not 16MB)
 ```
 
+**Subsetting performance** (Node.js benchmark, Lingdong Qiji Fuke, avg of 50 rounds):
+
+| Case | ttf | woff2 | Output size |
+|------|-----|-------|-------------|
+| Latin + digits (Hello World 123) | **0.11ms** | 0.13ms | 0.4KB |
+| 8 CJK characters | **0.17ms** | 0.38ms | 8KB |
+| Thousand Character Classic excerpt (88 chars) | **0.37ms** | 2.11ms | 78KB |
+
+Small character sets (the common case) hit **sub-millisecond** subsetting; time scales linearly with glyph count, with woff2's extra cost from brotli compression (a native hard limit). Response headers `X-Timing-Find/Read/Subset/Total` expose per-stage timing.
+
 JS SDK with three loading modes:
 
 ```html
diff --git a/README.md b/README.md
index 70daee0..6391770 100644
--- a/README.md
+++ b/README.md
@@ -42,6 +42,16 @@
 6 个字 → 服务端裁剪 → 返回约 6KB 子集字体（而非 16MB 完整字体）
 ```
 
+**裁剪性能**（Node.js 实测，令东齐伋复刻体，50 轮平均值）：
+
+| 场景 | ttf | woff2 | 输出大小 |
+|------|-----|-------|----------|
+| 拉丁 + 数字（Hello World 123） | **0.11ms** | 0.13ms | 0.4KB |
+| 8 个汉字 | **0.17ms** | 0.38ms | 8KB |
+| 千字文前段（88 字） | **0.37ms** | 2.11ms | 78KB |
+
+小字集（常用场景）裁剪已达**亚毫秒级**；耗时随字形数量线性增长，woff2 的额外开销来自 brotli 压缩（原生硬下限）。响应头 `X-Timing-Find/Read/Subset/Total` 可观测各阶段耗时。
+
 JS SDK 三种加载模式：
 
 ```html