diff --git a/doc/api/zlib.md b/doc/api/zlib.md
index 29af88ab40c2a1..cf9abd829babe7 100644
--- a/doc/api/zlib.md
+++ b/doc/api/zlib.md
@@ -496,6 +496,8 @@ See [below][Brotli parameters] for more details on Brotli-specific options.
 
 ### For Zstd-based streams
 
+> Stability: 1 - Experimental
+
 There are equivalents to the zlib options for Zstd-based streams, although
 these options have different ranges than the zlib ones:
 
@@ -720,6 +722,8 @@ These advanced options are available for controlling decompression:
 
 ### Zstd constants
 
+> Stability: 1 - Experimental
+
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@@ -729,6 +733,8 @@ streams:
 
 #### Flush operations
 
+> Stability: 1 - Experimental
+
 The following values are valid flush operations for Zstd-based streams:
 
 * `zlib.constants.ZSTD_e_continue` (default for all operations)
@@ -737,6 +743,8 @@ The following values are valid flush operations for Zstd-based streams:
 
 #### Compressor options
 
+> Stability: 1 - Experimental
+
 There are several options that can be set on Zstd encoders, affecting
 compression efficiency and speed. Both the keys and the values can be accessed
 as properties of the `zlib.constants` object.
@@ -749,12 +757,16 @@ The most important options are:
 
 #### Pledged Source Size
 
+> Stability: 1 - Experimental
+
 It's possible to specify the expected total size of the uncompressed input via
 `opts.pledgedSrcSize`. If the size doesn't match at the end of the input,
 compression will fail with the code `ZSTD_error_srcSize_wrong`.
 
 #### Decompressor options
 
+> Stability: 1 - Experimental
+
 These advanced options are available for controlling decompression:
 
 * `ZSTD_d_windowLogMax`
@@ -1025,6 +1037,8 @@ the inflate and deflate algorithms.
 
 ## Class: `ZstdOptions`
 
+> Stability: 1 - Experimental
+
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@@ -1054,6 +1068,8 @@ const stream = zlib.createZstdCompress({
 
 ## Class: `zlib.ZstdCompress`
 
+> Stability: 1 - Experimental
+
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@@ -1062,6 +1078,8 @@ Compress data using the Zstd algorithm.
 
 ## Class: `zlib.ZstdDecompress`
 
+> Stability: 1 - Experimental
+
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@@ -1243,6 +1261,8 @@ Creates and returns a new [`Unzip`][] object.
 
 ## `zlib.createZstdCompress([options])`
 
+> Stability: 1 - Experimental
+
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@@ -1253,6 +1273,8 @@ Creates and returns a new [`ZstdCompress`][] object.
 
 ## `zlib.createZstdDecompress([options])`
 
+> Stability: 1 - Experimental
+
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@@ -1609,6 +1631,8 @@ Decompress a chunk of data with [`Unzip`][].
 
 ### `zlib.zstdCompress(buffer[, options], callback)`
 
+> Stability: 1 - Experimental
+
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@@ -1619,6 +1643,8 @@ added: REPLACEME
 
 ### `zlib.zstdCompressSync(buffer[, options])`
 
+> Stability: 1 - Experimental
+
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@@ -1640,6 +1666,8 @@ added: REPLACEME
 
 ### `zlib.zstdDecompressSync(buffer[, options])`
 
+> Stability: 1 - Experimental
+
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