Fix documented default for WebSocketResponse writer_limit

[LALITH0110]

What do these changes do?

Correct the documented default for WebSocketResponse's writer_limit parameter in docs/web_reference.rst.

The reference documented it in two places:

• the class signature, as writer_limit=65536
• the parameter description, as "maximum size of write buffer, 64 KB by default"

The actual default in aiohttp/web_ws.py is writer_limit: int = DEFAULT_CHUNK_SIZE, and DEFAULT_CHUNK_SIZE is 2**18 in aiohttp/helpers.py — that is 262144 bytes, or 256 KiB. So the documented value understated the real default by a factor of four.

The signature now reads writer_limit=262144, matching how the neighbouring max_msg_size=4194304 is written, and the prose now says "256 KiB by default".

Documentation only — no code changes.

Are there changes in behavior for the user?

No. Nothing in the library changes. Users reading the docs to size a WebSocket write buffer will now see the value the code actually uses.

Is it a substantial burden for the maintainers to support this?

No. It is a two-line documentation correction with no ongoing maintenance cost.

Related issue number

None — found while comparing documented parameter defaults against the actual signatures.

Checklist

• I think the code is well written
• Unit tests for the changes exist — N/A, documentation-only change
• Documentation reflects the changes
• If you provide code modification, please add yourself to CONTRIBUTORS.txt
• Add a new news fragment into the CHANGES/ folder

Drafted with Claude Opus 5; reviewed by @LALITH0110.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.02%. Comparing base (5836019) to head (c8a3bb6).
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@           Coverage Diff           @@
##           master   #13294   +/-   ##
=======================================
  Coverage   99.02%   99.02%           
=======================================
  Files         135      135           
  Lines       49992    49992           
  Branches     2597     2597           
=======================================
  Hits        49507    49507           
  Misses        366      366           
  Partials      119      119           

Flag	Coverage Δ
Autobahn	22.02% <ø> (ø)
CI-GHA	98.93% <ø> (+<0.01%)	⬆️
OS-Linux	98.70% <ø> (+<0.01%)	⬆️
OS-Windows	97.04% <ø> (+<0.01%)	⬆️
OS-macOS	97.95% <ø> (ø)
Py-3.10	98.15% <ø> (ø)
Py-3.11	98.39% <ø> (+<0.01%)	⬆️
Py-3.12	98.47% <ø> (ø)
Py-3.13	98.47% <ø> (+<0.01%)	⬆️
Py-3.14	98.48% <ø> (-0.01%)	⬇️
Py-3.14t	97.57% <ø> (ø)
Py-pypy-3.11	97.43% <ø> (-0.01%)	⬇️
VM-macos	97.95% <ø> (ø)
VM-ubuntu	98.70% <ø> (+<0.01%)	⬆️
VM-windows	97.04% <ø> (+<0.01%)	⬆️
cython-coverage	83.01% <ø> (ø)

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[codspeed]

Merging this PR will degrade performance by 2.44%

⚠️ Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

⚡ 1 improved benchmark
❌ 2 (👁 2) regressed benchmarks
✅ 89 untouched benchmarks
⏩ 83 skipped benchmarks¹

Performance Changes

	Benchmark	BASE	HEAD	Efficiency
⚡	test_read_base64_part	16 ms	14.1 ms	+13.06%
👁	test_list_element_pattern_redos_payload[interleaved_quote_paren_triggers]	87.5 ms	96.4 ms	-9.25%
👁	test_list_element_pattern_redos_payload[whitespace_run_after_content]	30.9 ms	34.2 ms	-9.49%

Tip

Curious why this is faster? Comment @codspeedbot explain why this is faster on this PR, or directly use the CodSpeed MCP with your agent.

---

_{Comparing LALITH0110:docs/websocketresponse-writer-limit-default (c8a3bb6) with master (5836019)}

Footnotes

1. 83 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[greptile-apps]

Confidence Score: 5/5

The PR appears safe to merge.

No blocking failure remains.

_{Reviews (2): Last reviewed commit: "Update web_reference.rst" | Re-trigger Greptile}

[patchback]

Backport to 3.15: 💔 cherry-picking failed — conflicts found

❌ Failed to cleanly apply f1c70aa on top of patchback/backports/3.15/f1c70aa4b9160798603f56fd84937d78741ada53/pr-13294

Backporting merged PR #13294 into master

1. Ensure you have a local repo clone of your fork. Unless you cloned it
   from the upstream, this would be your origin remote.
2. Make sure you have an upstream repo added as a remote too. In these
   instructions you'll refer to it by the name upstream. If you don't
   have it, here's how you can add it:

   $ git remote add upstream https://github.com/aio-libs/aiohttp.git

3. Ensure you have the latest copy of upstream and prepare a branch
   that will hold the backported code:

   $ git fetch upstream
   $ git checkout -b patchback/backports/3.15/f1c70aa4b9160798603f56fd84937d78741ada53/pr-13294 upstream/3.15

4. Now, cherry-pick PR Fix documented default for WebSocketResponse writer_limit #13294 contents into that branch:

   $ git cherry-pick -x f1c70aa4b9160798603f56fd84937d78741ada53

   If it'll yell at you with something like fatal: Commit f1c70aa4b9160798603f56fd84937d78741ada53 is a merge but no -m option was given., add -m 1 as follows instead:

   $ git cherry-pick -m1 -x f1c70aa4b9160798603f56fd84937d78741ada53

5. At this point, you'll probably encounter some merge conflicts. You must
   resolve them in to preserve the patch from PR Fix documented default for WebSocketResponse writer_limit #13294 as close to the
   original as possible.
6. Push this branch to your fork on GitHub:

   $ git push origin patchback/backports/3.15/f1c70aa4b9160798603f56fd84937d78741ada53/pr-13294

7. Create a PR, ensure that the CI is green. If it's not — update it so that
   the tests and any other checks pass. This is it!
   Now relax and wait for the maintainers to process your pull request
   when they have some cycles to do reviews. Don't worry — they'll tell you if
   any improvements are necessary when the time comes!

🤖 @patchback
I'm built with octomachinery and
my source is open — https://github.com/sanitizers/patchback-github-app.

[patchback]

Backport to 3.14: 💔 cherry-picking failed — conflicts found

❌ Failed to cleanly apply f1c70aa on top of patchback/backports/3.14/f1c70aa4b9160798603f56fd84937d78741ada53/pr-13294

Backporting merged PR #13294 into master

1. Ensure you have a local repo clone of your fork. Unless you cloned it
   from the upstream, this would be your origin remote.
2. Make sure you have an upstream repo added as a remote too. In these
   instructions you'll refer to it by the name upstream. If you don't
   have it, here's how you can add it:

   $ git remote add upstream https://github.com/aio-libs/aiohttp.git

3. Ensure you have the latest copy of upstream and prepare a branch
   that will hold the backported code:

   $ git fetch upstream
   $ git checkout -b patchback/backports/3.14/f1c70aa4b9160798603f56fd84937d78741ada53/pr-13294 upstream/3.14

4. Now, cherry-pick PR Fix documented default for WebSocketResponse writer_limit #13294 contents into that branch:

   $ git cherry-pick -x f1c70aa4b9160798603f56fd84937d78741ada53

   If it'll yell at you with something like fatal: Commit f1c70aa4b9160798603f56fd84937d78741ada53 is a merge but no -m option was given., add -m 1 as follows instead:

   $ git cherry-pick -m1 -x f1c70aa4b9160798603f56fd84937d78741ada53

5. At this point, you'll probably encounter some merge conflicts. You must
   resolve them in to preserve the patch from PR Fix documented default for WebSocketResponse writer_limit #13294 as close to the
   original as possible.
6. Push this branch to your fork on GitHub:

   $ git push origin patchback/backports/3.14/f1c70aa4b9160798603f56fd84937d78741ada53/pr-13294

7. Create a PR, ensure that the CI is green. If it's not — update it so that
   the tests and any other checks pass. This is it!
   Now relax and wait for the maintainers to process your pull request
   when they have some cycles to do reviews. Don't worry — they'll tell you if
   any improvements are necessary when the time comes!

🤖 @patchback
I'm built with octomachinery and
my source is open — https://github.com/sanitizers/patchback-github-app.

[Dreamsorcerer]

Please follow instructions above for backports.