feat(webserver): add support for chunked HTTP responses Fixes #5080 #11894

ritesh006 · 2025-10-03T14:17:47Z

Enhance the ESP32 WebServer library by introducing native support for chunked transfer encoding. This allows streaming large or dynamic content efficiently, improving scalability and performance. Adds three main methods: chunkedResponseModeStart(), sendChunk(), and chunkedResponseFinalize() for easy, reliable implementation of chunked responses

Fixes #5080

CLAassistant · 2025-10-03T14:17:58Z

All committers have signed the CLA.

github-actions · 2025-10-03T14:18:27Z

	Warnings
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libraries/WebServer/src/WebServer.h

me-no-dev · 2025-10-03T14:35:25Z

libraries/WebServer/src/WebServer.cpp

+}
+
+void WebServer::sendChunk(const char* data, size_t length) {
+  if (!_chunkedResponseActive) return;


log_e that chunk response has not been started

libraries/WebServer/src/WebServer.cpp

me-no-dev · 2025-10-03T14:38:15Z

Please also add a small example to showcase the usage

to WebServer library for chunked HTTP responses

ritesh006 · 2025-10-03T14:58:15Z

Ready for Review

github-actions · 2025-10-03T15:54:19Z

Test Results

76 files 76 suites 13m 52s ⏱️
38 tests 38 ✅ 0 💤 0 ❌
241 runs 241 ✅ 0 💤 0 ❌

Results for commit dfaa04b.

♻️ This comment has been updated with latest results.

github-actions · 2025-10-03T15:56:28Z

Memory usage test (comparing PR against master branch)

The table below shows the summary of memory usage change (decrease - increase) in bytes and percentage for each target.

Memory	FLASH [bytes]		FLASH [%]		RAM [bytes]		RAM [%]
Target	DEC	INC	DEC	INC	DEC	INC	DEC	INC
ESP32C5	0	⚠️ +46	0.00	0.00	0	⚠️ +64	0.00	⚠️ +0.14
ESP32P4	0	⚠️ +46	0.00	⚠️ +0.01	0	⚠️ +64	0.00	⚠️ +0.20
ESP32S3	0	⚠️ +152	0.00	⚠️ +0.02	0	⚠️ +56	0.00	⚠️ +0.12
ESP32S2	0	⚠️ +156	0.00	⚠️ +0.02	0	⚠️ +56	0.00	⚠️ +0.14
ESP32C3	0	⚠️ +46	0.00	0.00	0	⚠️ +64	0.00	⚠️ +0.18
ESP32C6	0	⚠️ +46	0.00	0.00	0	⚠️ +64	0.00	⚠️ +0.15
ESP32	0	⚠️ +160	0.00	⚠️ +0.02	0	⚠️ +56	0.00	⚠️ +0.12

Click to expand the detailed deltas report [usage change in BYTES]

Target	ESP32C5		ESP32P4		ESP32S3		ESP32S2		ESP32C3		ESP32C6		ESP32
Example	FLASH	RAM	FLASH	RAM	FLASH	RAM	FLASH	RAM	FLASH	RAM	FLASH	RAM	FLASH	RAM
libraries/DNSServer/examples/CaptivePortal	⚠️ +16	⚠️ +64	⚠️ +12	⚠️ +48	⚠️ +112	⚠️ +56	⚠️ +112	⚠️ +56	⚠️ +16	⚠️ +64	⚠️ +16	⚠️ +48	⚠️ +116	⚠️ +56
libraries/HTTPUpdateServer/examples/WebUpdater	⚠️ +16	⚠️ +48	⚠️ +16	⚠️ +64	⚠️ +120	⚠️ +56	⚠️ +120	⚠️ +56	⚠️ +16	⚠️ +48	⚠️ +16	⚠️ +48	⚠️ +116	⚠️ +56
libraries/Update/examples/HTTP_Server_AES_OTA_Update	⚠️ +12	⚠️ +48	⚠️ +12	⚠️ +64	⚠️ +116	⚠️ +56	⚠️ +116	⚠️ +56	⚠️ +16	⚠️ +48	⚠️ +12	⚠️ +48	⚠️ +116	⚠️ +56
libraries/Update/examples/OTAWebUpdater	⚠️ +12	⚠️ +64	⚠️ +12	⚠️ +48	⚠️ +120	⚠️ +56	⚠️ +124	⚠️ +56	⚠️ +12	⚠️ +64	⚠️ +12	⚠️ +64	⚠️ +116	⚠️ +56
libraries/WebServer/examples/AdvancedWebServer	⚠️ +16	⚠️ +48	⚠️ +16	⚠️ +64	⚠️ +112	⚠️ +56	⚠️ +120	⚠️ +56	⚠️ +16	⚠️ +48	⚠️ +16	⚠️ +64	⚠️ +116	⚠️ +56
libraries/WebServer/examples/ChunkWriting	-	-	-	-	-	-	-	-	-	-	-	-	-	-
libraries/WebServer/examples/FSBrowser	⚠️ +12	⚠️ +64	⚠️ +12	⚠️ +48	⚠️ +112	⚠️ +56	⚠️ +112	⚠️ +56	⚠️ +12	⚠️ +64	⚠️ +12	⚠️ +64	⚠️ +116	⚠️ +56
libraries/WebServer/examples/Filters	⚠️ +16	⚠️ +48	⚠️ +16	⚠️ +64	⚠️ +112	⚠️ +56	⚠️ +112	⚠️ +56	⚠️ +16	⚠️ +48	⚠️ +16	⚠️ +64	⚠️ +116	⚠️ +56
libraries/WebServer/examples/HelloServer	⚠️ +16	⚠️ +48	⚠️ +16	⚠️ +64	⚠️ +112	⚠️ +56	⚠️ +112	⚠️ +56	⚠️ +16	⚠️ +48	⚠️ +16	⚠️ +64	⚠️ +116	⚠️ +56
libraries/WebServer/examples/HttpAdvancedAuth	⚠️ +12	⚠️ +48	⚠️ +12	⚠️ +64	⚠️ +112	⚠️ +56	⚠️ +112	⚠️ +56	⚠️ +16	⚠️ +48	⚠️ +12	⚠️ +64	⚠️ +116	⚠️ +56
libraries/WebServer/examples/HttpAuthCallback	⚠️ +12	⚠️ +48	⚠️ +12	⚠️ +64	⚠️ +116	⚠️ +56	⚠️ +116	⚠️ +56	⚠️ +16	⚠️ +48	⚠️ +12	⚠️ +64	⚠️ +116	⚠️ +56
libraries/WebServer/examples/HttpAuthCallbackInline	⚠️ +12	⚠️ +48	⚠️ +12	⚠️ +64	⚠️ +116	⚠️ +56	⚠️ +116	⚠️ +56	⚠️ +16	⚠️ +48	⚠️ +12	⚠️ +64	⚠️ +116	⚠️ +56
libraries/WebServer/examples/HttpBasicAuth	⚠️ +12	⚠️ +48	⚠️ +12	⚠️ +64	⚠️ +112	⚠️ +56	⚠️ +112	⚠️ +56	⚠️ +16	⚠️ +48	⚠️ +12	⚠️ +64	⚠️ +116	⚠️ +56
libraries/WebServer/examples/HttpBasicAuthSHA1	⚠️ +16	⚠️ +48	⚠️ +16	⚠️ +64	⚠️ +116	⚠️ +56	⚠️ +120	⚠️ +56	⚠️ +12	⚠️ +48	⚠️ +16	⚠️ +64	⚠️ +112	⚠️ +56
libraries/WebServer/examples/HttpBasicAuthSHA1orBearerToken	⚠️ +16	⚠️ +48	⚠️ +16	⚠️ +64	⚠️ +112	⚠️ +56	⚠️ +112	⚠️ +56	⚠️ +12	⚠️ +48	⚠️ +16	⚠️ +48	⚠️ +112	⚠️ +56
libraries/WebServer/examples/Middleware	⚠️ +12	⚠️ +64	-	-	⚠️ +112	⚠️ +56	⚠️ +112	⚠️ +56	⚠️ +12	⚠️ +64	⚠️ +12	⚠️ +48	⚠️ +124	⚠️ +56
libraries/WebServer/examples/MultiHomedServers	⚠️ +46	0	⚠️ +46	0	⚠️ +152	0	⚠️ +156	0	⚠️ +46	0	⚠️ +46	0	⚠️ +160	0
libraries/WebServer/examples/PathArgServer	⚠️ +16	⚠️ +48	⚠️ +16	⚠️ +64	⚠️ +112	⚠️ +56	⚠️ +116	⚠️ +56	⚠️ +16	⚠️ +48	⚠️ +16	⚠️ +64	⚠️ +120	⚠️ +56
libraries/WebServer/examples/SDWebServer	⚠️ +12	⚠️ +48	⚠️ +12	⚠️ +64	⚠️ +112	⚠️ +56	⚠️ +112	⚠️ +56	⚠️ +12	⚠️ +48	⚠️ +12	⚠️ +48	⚠️ +116	⚠️ +56
libraries/WebServer/examples/SimpleAuthentification	⚠️ +16	⚠️ +64	⚠️ +16	⚠️ +48	⚠️ +112	⚠️ +56	⚠️ +116	⚠️ +56	⚠️ +16	⚠️ +64	⚠️ +16	⚠️ +64	⚠️ +116	⚠️ +56
libraries/WebServer/examples/UploadHugeFile	⚠️ +12	⚠️ +48	⚠️ +12	⚠️ +64	⚠️ +116	⚠️ +56	⚠️ +116	⚠️ +56	⚠️ +12	⚠️ +48	⚠️ +12	⚠️ +64	⚠️ +116	⚠️ +56
libraries/WebServer/examples/WebServer	⚠️ +12	⚠️ +48	⚠️ +16	⚠️ +64	⚠️ +116	⚠️ +56	⚠️ +120	⚠️ +56	⚠️ +16	⚠️ +48	⚠️ +16	⚠️ +48	⚠️ +116	⚠️ +56
libraries/WebServer/examples/WebUpdate	⚠️ +12	⚠️ +64	⚠️ +12	⚠️ +48	⚠️ +112	⚠️ +56	⚠️ +112	⚠️ +56	⚠️ +12	⚠️ +64	⚠️ +12	⚠️ +48	⚠️ +112	⚠️ +56

ritesh006 · 2025-10-04T04:42:13Z

Hi @me-no-dev May I please know when this commit is planned to be merged?

me-no-dev · 2025-10-04T10:18:51Z

@ritesh006 let's give a chance for others to review as well. It will be part of next release

ritesh006 · 2025-10-04T12:04:20Z

@ritesh006 let's give a chance for others to review as well. It will be part of next release

Yes thank so much

SuGlider

All good! Thanks @ritesh006 for the PR!

$ curl -i esp32_chunk_resp.local:80
HTTP/1.1 200 OK
Content-Type: text/plain
Accept-Ranges: none
Transfer-Encoding: chunked
Connection: close

10...
9...
8...
7...
6...
5...
4...
3...
2...
1...
DONE!

This example demonstrates how to send an HTTP response using chunks with an ESP32 server. It includes setup for WiFi, MDNS, and handles HTTP requests with chunked responses.

libraries/WebServer/examples/ChunkWriting/ChunkWriting.ino

ritesh006 · 2025-10-05T05:49:21Z

Thank You @SuGlider

me-no-dev · 2025-10-06T07:55:13Z

@lucasssvaz PTAL

lucasssvaz

LGTM

ritesh006 requested a review from a team as a code owner October 3, 2025 14:17

ritesh006 changed the title ~~Add chunked HTTP response support to ESP32 Arduino WebServer library Fixes #5080~~ feat(webserver): add support for chunked HTTP responses Fixes #5080 Oct 3, 2025

me-no-dev reviewed Oct 3, 2025

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ritesh006 force-pushed the feature/chunked-response branch from c1a5c63 to bf6aed6 Compare October 3, 2025 14:42

Add chunkedResponseModeStart, sendChunk, chunkedResponseFinalize

f4f8762

to WebServer library for chunked HTTP responses

ritesh006 force-pushed the feature/chunked-response branch from bf6aed6 to f4f8762 Compare October 3, 2025 14:57

me-no-dev approved these changes Oct 3, 2025

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Merge branch 'master' into feature/chunked-response

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me-no-dev added the Status: Review needed Issue or PR is awaiting review label Oct 4, 2025

SuGlider self-requested a review October 4, 2025 19:22

SuGlider approved these changes Oct 4, 2025

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SuGlider added 2 commits October 4, 2025 16:30

feat(webserver): Chunk example for ESP32 HTTP server

c1b8036

This example demonstrates how to send an HTTP response using chunks with an ESP32 server. It includes setup for WiFi, MDNS, and handles HTTP requests with chunked responses.

feat(webserver): Add ci.json for ChunkWriting example configuration

0310c97

SuGlider requested a review from lucasssvaz as a code owner October 4, 2025 19:31

SuGlider reviewed Oct 4, 2025

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fix(example): not necessary code line

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P-R-O-C-H-Y approved these changes Oct 6, 2025

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me-no-dev added Status: Pending Merge Pull Request is ready to be merged and removed Status: Review needed Issue or PR is awaiting review labels Oct 6, 2025

ci(pre-commit): Apply automatic fixes

dfaa04b

lucasssvaz approved these changes Oct 6, 2025

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me-no-dev merged commit 9d44061 into espressif:master Oct 6, 2025
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feat(webserver): add support for chunked HTTP responses Fixes #5080 #11894

feat(webserver): add support for chunked HTTP responses Fixes #5080 #11894

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