Reduce core bundle size in v11 by JoviDeCroock · Pull Request #5167 · preactjs/preact

JoviDeCroock · 2026-07-18T05:43:29Z

Co-locating cloneElement with createElement benefits gzip with 8 bytes
We can check handled for error-checking once and later
We don't have to check oldVNode in children because it's always true (default empty_obj)
Reduce the mathml regex

Simplify core control flow and reuse existing constants to reduce the production bundle from 4,857 to 4,814 bytes gzip while preserving behavior.

Keep createElement and cloneElement normalization together and reuse their argument counts. This reduces core from 4,814 to 4,804 bytes gzip without adding runtime work.

Restore the existing isValidElement declaration and remove the obsolete cloneElement re-export module. This leaves core at 4,806 bytes gzip while narrowing source churn.

github-actions · 2026-07-18T05:43:50Z

📊 Tachometer Benchmark Results

Summary

duration

create10k: slower ❌ 0% - 2% (3.81ms - 13.71ms)
^{preact-local vs preact-main}
filter-list: unsure 🔍 -0% - +1% (-0.02ms - +0.13ms)
^{preact-local vs preact-main}
hydrate1k: unsure 🔍 -0% - +2% (-0.18ms - +0.89ms)
^{preact-local vs preact-main}
many-updates: unsure 🔍 -1% - +0% (-0.15ms - +0.06ms)
^{preact-local vs preact-main}
replace1k: slower ❌ 2% - 6% (1.08ms - 3.09ms)
^{preact-local vs preact-main}
text-update: unsure 🔍 -5% - +3% (-0.08ms - +0.04ms)
^{preact-local vs preact-main}
todo: unsure 🔍 -2% - +0% (-0.74ms - +0.15ms)
^{preact-local vs preact-main}
update10th1k: unsure 🔍 -1% - +5% (-0.38ms - +1.57ms)
^{preact-local vs preact-main}

usedJSHeapSize

create10k: unsure 🔍 -0% - -0% (-0.00ms - -0.00ms)
^{preact-local vs preact-main}
filter-list: unsure 🔍 -0% - -0% (-0.00ms - -0.00ms)
^{preact-local vs preact-main}
hydrate1k: unsure 🔍 -2% - +1% (-0.11ms - +0.03ms)
^{preact-local vs preact-main}
many-updates: unsure 🔍 -0% - -0% (-0.00ms - -0.00ms)
^{preact-local vs preact-main}
replace1k: unsure 🔍 -0% - -0% (-0.00ms - -0.00ms)
^{preact-local vs preact-main}
text-update: unsure 🔍 -2% - +3% (-0.03ms - +0.03ms)
^{preact-local vs preact-main}
todo: unsure 🔍 -0% - -0% (-0.00ms - -0.00ms)
^{preact-local vs preact-main}
update10th1k: unsure 🔍 -0% - +0% (-0.01ms - +0.01ms)
^{preact-local vs preact-main}

Results

create10k

Browser: chrome-headless
Sample size: 50
Built by: CI #5697
Commit: 529bc4b

duration

Version	Avg time	vs preact-local	vs preact-main
preact-local	826.51ms - 834.82ms	-	slower ❌ 0% - 2% 3.81ms - 13.71ms
preact-main	819.22ms - 824.60ms	faster ✔ 0% - 2% 3.81ms - 13.71ms	-

usedJSHeapSize

Version	Avg time	vs preact-local	vs preact-main
preact-local	19.08ms - 19.08ms	-	unsure 🔍 -0% - -0% -0.00ms - -0.00ms
preact-main	19.08ms - 19.08ms	unsure 🔍 +0% - +0% +0.00ms - +0.00ms	-

filter-list

Browser: chrome-headless
Sample size: 50
Built by: CI #5697
Commit: 529bc4b

duration

Version	Avg time	vs preact-local	vs preact-main
preact-local	16.55ms - 16.69ms	-	unsure 🔍 -0% - +1% -0.02ms - +0.13ms
preact-main	16.54ms - 16.59ms	unsure 🔍 -1% - +0% -0.13ms - +0.02ms	-

usedJSHeapSize

Version	Avg time	vs preact-local	vs preact-main
preact-local	1.55ms - 1.55ms	-	unsure 🔍 -0% - -0% -0.00ms - -0.00ms
preact-main	1.55ms - 1.55ms	unsure 🔍 +0% - +0% +0.00ms - +0.00ms	-

hydrate1k

Browser: chrome-headless
Sample size: 50
Built by: CI #5697
Commit: 529bc4b

duration

Version	Avg time	vs preact-local	vs preact-main
preact-local	54.99ms - 55.62ms	-	unsure 🔍 -0% - +2% -0.18ms - +0.89ms
preact-main	54.51ms - 55.38ms	unsure 🔍 -2% - +0% -0.89ms - +0.18ms	-

usedJSHeapSize

Version	Avg time	vs preact-local	vs preact-main
preact-local	5.00ms - 5.00ms	-	unsure 🔍 -2% - +1% -0.11ms - +0.03ms
preact-main	4.97ms - 5.11ms	unsure 🔍 -1% - +2% -0.03ms - +0.11ms	-

many-updates

Browser: chrome-headless
Sample size: 50
Built by: CI #5697
Commit: 529bc4b

duration

Version	Avg time	vs preact-local	vs preact-main
preact-local	16.42ms - 16.56ms	-	unsure 🔍 -1% - +0% -0.15ms - +0.06ms
preact-main	16.46ms - 16.61ms	unsure 🔍 -0% - +1% -0.06ms - +0.15ms	-

usedJSHeapSize

Version	Avg time	vs preact-local	vs preact-main
preact-local	3.74ms - 3.74ms	-	unsure 🔍 -0% - -0% -0.00ms - -0.00ms
preact-main	3.74ms - 3.75ms	unsure 🔍 +0% - +0% +0.00ms - +0.00ms	-

replace1k

Browser: chrome-headless
Sample size: 100
Built by: CI #5697
Commit: 529bc4b

duration

Version	Avg time	vs preact-local	vs preact-main
preact-local	55.93ms - 57.63ms	-	slower ❌ 2% - 6% 1.08ms - 3.09ms
preact-main	54.16ms - 55.23ms	faster ✔ 2% - 5% 1.08ms - 3.09ms	-

usedJSHeapSize

Version	Avg time	vs preact-local	vs preact-main
preact-local	3.01ms - 3.01ms	-	unsure 🔍 -0% - -0% -0.00ms - -0.00ms
preact-main	3.01ms - 3.01ms	unsure 🔍 +0% - +0% +0.00ms - +0.00ms	-

run-warmup-0

Version	Avg time	vs preact-local	vs preact-main
preact-local	29.78ms - 30.47ms	-	slower ❌ 2% - 6% 0.52ms - 1.68ms
preact-main	28.56ms - 29.50ms	faster ✔ 2% - 6% 0.52ms - 1.68ms	-

run-warmup-1

Version	Avg time	vs preact-local	vs preact-main
preact-local	34.28ms - 35.68ms	-	unsure 🔍 -1% - +5% -0.38ms - +1.60ms
preact-main	33.67ms - 35.07ms	unsure 🔍 -5% - +1% -1.60ms - +0.38ms	-

run-warmup-2

Version	Avg time	vs preact-local	vs preact-main
preact-local	30.78ms - 32.12ms	-	slower ❌ 2% - 8% 0.71ms - 2.50ms
preact-main	29.25ms - 30.45ms	faster ✔ 2% - 8% 0.71ms - 2.50ms	-

run-warmup-3

Version	Avg time	vs preact-local	vs preact-main
preact-local	26.62ms - 27.39ms	-	slower ❌ 2% - 6% 0.65ms - 1.49ms
preact-main	25.76ms - 26.10ms	faster ✔ 2% - 5% 0.65ms - 1.49ms	-

run-warmup-4

Version	Avg time	vs preact-local	vs preact-main
preact-local	23.87ms - 25.33ms	-	unsure 🔍 -2% - +6% -0.56ms - +1.51ms
preact-main	23.39ms - 24.86ms	unsure 🔍 -6% - +2% -1.51ms - +0.56ms	-

run-final

Version	Avg time	vs preact-local	vs preact-main
preact-local	21.49ms - 22.36ms	-	slower ❌ 4% - 9% 0.89ms - 1.82ms
preact-main	20.40ms - 20.73ms	faster ✔ 4% - 8% 0.89ms - 1.82ms	-

text-update

Browser: chrome-headless
Sample size: 240
Built by: CI #5697
Commit: 529bc4b

duration

Version	Avg time	vs preact-local	vs preact-main
preact-local	1.57ms - 1.65ms	-	unsure 🔍 -5% - +3% -0.08ms - +0.04ms
preact-main	1.58ms - 1.67ms	unsure 🔍 -3% - +5% -0.04ms - +0.08ms	-

usedJSHeapSize

Version	Avg time	vs preact-local	vs preact-main
preact-local	1.02ms - 1.05ms	-	unsure 🔍 -2% - +3% -0.03ms - +0.03ms
preact-main	1.02ms - 1.05ms	unsure 🔍 -3% - +2% -0.03ms - +0.03ms	-

todo

Browser: chrome-headless
Sample size: 50
Built by: CI #5697
Commit: 529bc4b

duration

Version	Avg time	vs preact-local	vs preact-main
preact-local	32.66ms - 33.04ms	-	unsure 🔍 -2% - +0% -0.74ms - +0.15ms
preact-main	32.74ms - 33.55ms	unsure 🔍 -0% - +2% -0.15ms - +0.74ms	-

usedJSHeapSize

Version	Avg time	vs preact-local	vs preact-main
preact-local	1.26ms - 1.26ms	-	unsure 🔍 -0% - -0% -0.00ms - -0.00ms
preact-main	1.27ms - 1.27ms	unsure 🔍 +0% - +0% +0.00ms - +0.00ms	-

update10th1k

Browser: chrome-headless
Sample size: 80
Built by: CI #5697
Commit: 529bc4b

duration

Version	Avg time	vs preact-local	vs preact-main
preact-local	32.45ms - 33.78ms	-	unsure 🔍 -1% - +5% -0.38ms - +1.57ms
preact-main	31.81ms - 33.22ms	unsure 🔍 -5% - +1% -1.57ms - +0.38ms	-

usedJSHeapSize

Version	Avg time	vs preact-local	vs preact-main
preact-local	2.97ms - 2.98ms	-	unsure 🔍 -0% - +0% -0.01ms - +0.01ms
preact-main	2.97ms - 2.98ms	unsure 🔍 -0% - +0% -0.01ms - +0.01ms	-

_{tachometer-reporter-action v2 for CI}

github-actions · 2026-07-18T05:44:19Z

Size Change: -50 B (-0.32%)

Total Size: 15.8 kB

📦 View Changed

Filename	Size	Change
`dist/preact.mjs`	4.84 kB	-50 B (-1.02%)

ℹ️ View Unchanged

Filename	Size
`compat/dist/compat.mjs`	3.87 kB
`debug/dist/debug.mjs`	3.89 kB
`devtools/dist/devtools.mjs`	274 B
`hooks/dist/hooks.mjs`	1.55 kB
`jsx-runtime/dist/jsxRuntime.mjs`	861 B
`test-utils/dist/testUtils.mjs`	473 B

_{compressed-size-action}

coveralls · 2026-07-18T05:45:49Z

coverage: 98.534%. remained the same — JoviDeCroock/reduce-core-bundle-size into main

JoviDeCroock added 3 commits July 17, 2026 21:12

perf(core): reduce minified bundle size

441f356

Simplify core control flow and reuse existing constants to reduce the production bundle from 4,857 to 4,814 bytes gzip while preserving behavior.

perf(core): colocate element normalization

4003472

Keep createElement and cloneElement normalization together and reuse their argument counts. This reduces core from 4,814 to 4,804 bytes gzip without adding runtime work.

perf(core): trim element normalization diff

ee38478

Restore the existing isValidElement declaration and remove the obsolete cloneElement re-export module. This leaves core at 4,806 bytes gzip while narrowing source churn.

Merge branch 'main' into JoviDeCroock/reduce-core-bundle-size

529bc4b

Uh oh!

Uh oh!

Conversation

JoviDeCroock commented Jul 18, 2026

Uh oh!

github-actions Bot commented Jul 18, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

📊 Tachometer Benchmark Results

Summary

duration

usedJSHeapSize

Results

duration

usedJSHeapSize

duration

usedJSHeapSize

duration

usedJSHeapSize

duration

usedJSHeapSize

duration

usedJSHeapSize

run-warmup-0

run-warmup-1

run-warmup-2

run-warmup-3

run-warmup-4

run-final

duration

usedJSHeapSize

duration

usedJSHeapSize

duration

usedJSHeapSize

Uh oh!

github-actions Bot commented Jul 18, 2026

Uh oh!

coveralls commented Jul 18, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

github-actions Bot commented Jul 18, 2026 •

edited

Loading

coveralls commented Jul 18, 2026 •

edited

Loading