Files
homarr/docs/perf
Thomas Camlong fd351e4adf test(widgets): pin the Tabs behaviour that keepMounted={false} depends on
health-monitoring and media-missing pass keepMounted={false} because Mantine
otherwise builds the inactive panel's whole subtree. That came from reading
Mantine's docs, which is a weak basis for a prop that trades a remount cost for a
mount saving: if Mantine ever stopped rendering inactive panels, the prop would be
pure loss and nobody would notice.

Verified in the installed version instead. With three marker children per panel,
the default renders 3 of 3 children of the *inactive* panel into the DOM, and
keepMounted={false} renders 0. If that changes, this fails and the prop should
come back out.

Also records two things checked while re-reading the audit:

_inputs/ is excluded from the widget sweep on purpose, not by oversight - its
2,748 lines are option editors reached only from the edit modal and the
custom-widget form, and the one widget importing from it uses `import type`,
which is erased at build.

The "statically analyzable dynamic imports" rule has exactly one exception,
translation/src/mapping.ts building import(`./lang/${language}.json`) over 36
languages. It stands: the rule targets accidental over-inclusion, and every
language is genuinely reachable since the user can switch at runtime. Server-side
message loading is already memoised per locale, so it is not per-request either.
2026-08-13 18:28:29 +02:00
..

Homarr performance investigation

Measured work on Homarr's memory and rendering cost, split by subject. Every figure here comes from a run of scripts/benchmarks/stress-restore.mts against a restored real backup — 4 boards, 51 widgets, 11 integrations, driven through an actual login — not from a synthetic or empty container.

document subject
SERVER-MEMORY.md What the container's RAM is made of, and the changes that reduced it
CLIENT-PERFORMANCE.md Dashboard rendering cost in Chrome: DOM, fibers, images, paint
WIDGET-AUDIT.md All 50 widgets, one at a time, with a verdict and the evidence for each
REJECTED.md Ideas that were implemented and measured, then abandoned — with the numbers
METHODOLOGY.md The tools, and the measurement traps that produced wrong answers
NEXT-STEPS.md Handoff: what is unverified, what to do next, and the set for a clean PR

Headline result

Server RAM, merge-base 06724cfeb vs this branch, two alternated runs per side, reported as cgroup anonymous memory because that is what counts against a container limit and cannot be reclaimed:

stage before after change
peak 376.6 MiB 279.3 MiB −26%
boot idle 130.5 MiB 62.4 MiB −52%
after sign-in 247.4 MiB 142.9 MiB −42%
dashboard loaded 293.4 MiB 170.4 MiB −42%
4 tabs, 2 boards 366.5 MiB 258.2 MiB −30%
after 2 min idle soak 323.7 MiB 200.8 MiB −38%

No before/after range overlaps at any stage. The cost is +18% CPU (solid, non-overlapping).

The changes that did it, by ratio

change size effect
--max-semi-space-size=4 1 line −19% idle, −21% peak
preloadEntriesOnStart: false 1 line −52% anon at idle, 310 fewer files even at full load
Umami: stop fetching 100k raw events per refresh 1 file −26% peak, −93% transient buffers
serverExternalPackages (mysql2/pg + 8 more) 1 block −21 MiB idle
ssh2's 16 MiB WASM heap (docker-modem patch) 1 patch −15 to −18 MiB external
content-visibility on media-release cards 4 lines −59% image requests, −41% layout objects

What is left, and why it is hard

One lever has real headroom and it pays twice. Roughly 41 MiB of retained bundle source and ~38 MiB of V8 compiler zone memory both scale with how much JavaScript the server loads and compiles, and the largest single contributor is a 16.10 MiB subtree reached by every API route — the tRPC router importing every integration eagerly. Reducing that reduces both.

Everything else has been measured and closed: see REJECTED.md.