url: speed up WHATWG URL parsing by anonrig · Pull Request #65361 · nodejs/node · GitHub

Speeds up new URL() / URL.parse() on the common path: already-serialized ASCII hrefs.

The binding currently always:

Copies the V8 string into a UTF-8 buffer (Utf8Value)
Parses with Ada
Allocates a new V8 string from href, even when it is byte-identical to the input

Typical URLs (https://example.com/path, the whatwg-url-parse benchmark corpus) are one-byte ASCII and already in serialized form. This change:

Parses one-byte ASCII inputs in place via v8::String::ValueView (no UTF-8 copy)
Returns the original V8 string when href == input (no second string allocation)
Avoids copying the base URL into a temporary std::string just to parse it
Applies the same in-place parse to update() (setters re-parse an already-serialized href)
Delays URLContext allocation until parse finishes, and initializes it in one shot from urlComponents
Skips `${input}` when the value is already a string

Non-ASCII inputs still go through Utf8Value. Those results are never reused as the original string, because UTF-8 conversion may replace unpaired surrogates.

Benchmark

Same machine, Release build, benchmark/url/whatwg-url-parse.js e=12. Repeated runs:

Config	Before (ops/s)	After (ops/s)	Change
short / no base	7.82M	9.29M	+19%
long / no base	2.50M	2.75M	+10%
short / with base	2.94M	3.39M	+15%

dot (needs path normalization, so a new href string) is unchanged.

Review follow-up

reuse_input defaults to nullptr. Base-URL parse and update() omit it so we skip the O(n) href == input compare when the original V8 string will not be reused.

Tests

test/parallel/test-whatwg-url-*.js and test-url-*.js: 54 pass, 1 skip
WPT url: 5107 pass, 0 unexpected failures
New test/parallel/test-whatwg-url-parse-fast-path.js covers already-serialized ASCII hrefs, trailing-slash and dot-segment normalization, base resolution, non-string input, invalid input, unpaired surrogates, IDN, and setters

Assisted-by: Cursor

Review requested:

@nodejs/url

Codecov Report

❌ Patch coverage is 97.08738% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 90.11%. Comparing base (13fcd6f) to head (7589246).
⚠️ Report is 93 commits behind head on main.

Files with missing lines	Patch %	Lines
src/node_url.cc	93.18%	0 Missing and 3 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #65361      +/-   ##
==========================================
- Coverage   91.85%   90.11%   -1.74%     
==========================================
  Files         400      752     +352     
  Lines      178855   252356   +73501     
  Branches    27319    47474   +20155     
==========================================
+ Hits       164283   227413   +63130     
- Misses      14243    16224    +1981     
- Partials      329     8719    +8390

Files with missing lines	Coverage Δ
lib/internal/url.js	93.28% <100.00%> (+13.12%)	⬆️
src/node_url.cc	78.94% <93.18%> (ø)

... and 490 files with indirect coverage changes

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AI agents are not permitted to Signed-off-by

lgtm

Removed the Signed-off-by trailer from the commit(s). An AI agent cannot attest the DCO.

Parse one-byte ASCII inputs in place instead of copying them into a UTF-8 buffer, and reuse the original V8 string when the serialized href is unchanged. Delay URLContext allocation until parse finishes and skip ToString when the input is already a string. Signed-off-by: Yagiz Nizipli <yagiz@nizipli.com> Assisted-by: Cursor

I think we can avoid always comparing the strings here?

Base parsing and setters discard reuse_input, so here we can avoid an O(n) comparison no?

Resolved

LGTM, I think we can seperate PR same improvement for canParse?

Callers that never reuse the original V8 string (base URL parse and setters) now omit reuse_input so ParseUrlFromV8String does not compare href against the input. Signed-off-by: Yagiz Nizipli <yagiz@nizipli.com> Assisted-by: Cursor

lgtm

CI: https://ci.nodejs.org/job/node-test-pull-request/76112/

CI: https://ci.nodejs.org/job/node-test-pull-request/76135/

CI: https://ci.nodejs.org/job/node-test-pull-request/76163/

Lgtm

CI: https://ci.nodejs.org/job/node-test-pull-request/76223/

CI: https://ci.nodejs.org/job/node-test-pull-request/76236/

Landed in 2df4ce7...a8f9a7f

Parse one-byte ASCII inputs in place instead of copying them into a UTF-8 buffer, and reuse the original V8 string when the serialized href is unchanged. Delay URLContext allocation until parse finishes and skip ToString when the input is already a string. Signed-off-by: Yagiz Nizipli <yagiz@nizipli.com> Assisted-by: Cursor PR-URL: #65361 Reviewed-By: Matteo Collina <matteo.collina@gmail.com> Reviewed-By: Daniel Lemire <daniel@lemire.me> Reviewed-By: Gürgün Dayıoğlu <hey@gurgun.day>

Callers that never reuse the original V8 string (base URL parse and setters) now omit reuse_input so ParseUrlFromV8String does not compare href against the input. Signed-off-by: Yagiz Nizipli <yagiz@nizipli.com> Assisted-by: Cursor PR-URL: #65361 Reviewed-By: Matteo Collina <matteo.collina@gmail.com> Reviewed-By: Daniel Lemire <daniel@lemire.me> Reviewed-By: Gürgün Dayıoğlu <hey@gurgun.day>

Parse one-byte ASCII inputs in place instead of copying them into a UTF-8 buffer, and reuse the original V8 string when the serialized href is unchanged. Delay URLContext allocation until parse finishes and skip ToString when the input is already a string. Signed-off-by: Yagiz Nizipli <yagiz@nizipli.com> Assisted-by: Cursor PR-URL: #65361 Reviewed-By: Matteo Collina <matteo.collina@gmail.com> Reviewed-By: Daniel Lemire <daniel@lemire.me> Reviewed-By: Gürgün Dayıoğlu <hey@gurgun.day>

Callers that never reuse the original V8 string (base URL parse and setters) now omit reuse_input so ParseUrlFromV8String does not compare href against the input. Signed-off-by: Yagiz Nizipli <yagiz@nizipli.com> Assisted-by: Cursor PR-URL: #65361 Reviewed-By: Matteo Collina <matteo.collina@gmail.com> Reviewed-By: Daniel Lemire <daniel@lemire.me> Reviewed-By: Gürgün Dayıoğlu <hey@gurgun.day>

Parse one-byte ASCII inputs in place instead of copying them into a UTF-8 buffer, and reuse the original V8 string when the serialized href is unchanged. Delay URLContext allocation until parse finishes and skip ToString when the input is already a string. Signed-off-by: Yagiz Nizipli <yagiz@nizipli.com> Assisted-by: Cursor PR-URL: #65361 Reviewed-By: Matteo Collina <matteo.collina@gmail.com> Reviewed-By: Daniel Lemire <daniel@lemire.me> Reviewed-By: Gürgün Dayıoğlu <hey@gurgun.day>

Callers that never reuse the original V8 string (base URL parse and setters) now omit reuse_input so ParseUrlFromV8String does not compare href against the input. Signed-off-by: Yagiz Nizipli <yagiz@nizipli.com> Assisted-by: Cursor PR-URL: #65361 Reviewed-By: Matteo Collina <matteo.collina@gmail.com> Reviewed-By: Daniel Lemire <daniel@lemire.me> Reviewed-By: Gürgün Dayıoğlu <hey@gurgun.day>

nodejs-github-bot added c++ Issues and PRs that require attention from people who are familiar with C++. needs-ci PRs that need a full CI run. whatwg-url Issues and PRs related to the WHATWG URL implementation. labels Aug 18, 2026

anonrig requested review from jasnell and mcollina August 18, 2026 01:33

This was referenced Aug 18, 2026

url: speed up URLSearchParams #65363

Merged

url: speed up URLPattern anonrig/node#24

Open

url: speed up URLPattern #65364

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cursor Bot force-pushed the cursor/url-parse-performance-603e branch from b9884e1 to a66b5bc Compare August 18, 2026 11:39

cursor Bot force-pushed the cursor/url-parse-performance-603e branch from a66b5bc to 39c4db7 Compare August 18, 2026 12:49

cursor Bot force-pushed the cursor/url-parse-performance-603e branch 2 times, most recently from fa5ca3f to ed31ad0 Compare August 18, 2026 18:09

gurgunday reviewed Aug 18, 2026

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cursor Bot force-pushed the cursor/url-parse-performance-603e branch from ed31ad0 to 47af16c Compare August 18, 2026 18:43

mertcanaltin approved these changes Aug 19, 2026

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cursor Bot force-pushed the cursor/url-parse-performance-603e branch 2 times, most recently from faad7a6 to caa85b0 Compare August 20, 2026 18:57

url: skip unused href reuse comparison

7589246

Callers that never reuse the original V8 string (base URL parse and setters) now omit reuse_input so ParseUrlFromV8String does not compare href against the input. Signed-off-by: Yagiz Nizipli <yagiz@nizipli.com> Assisted-by: Cursor

cursor Bot force-pushed the cursor/url-parse-performance-603e branch from caa85b0 to 7589246 Compare August 20, 2026 18:57

anonrig requested review from jasnell, joyeecheung and lemire August 20, 2026 18:57

mcollina approved these changes Aug 21, 2026

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github-actions Bot mentioned this pull request Aug 25, 2026

2026-08-26, Version 26.8.0 (Current) #65551

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url: speed up WHATWG URL parsing by anonrig · Pull Request #65361 · nodejs/node · GitHub

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