HackerTube.dev

The Truth about Rust/WebAssembly Performance

Greg Johnston · 218K views · 2023-03-17 · 29:47

Open on YouTube ↗

If playback is restricted in your region, try opening the original video. Use Mark watched to add it to your marked videos.

Overview

Leptos creator Greg Johnston examines Rust/WebAssembly frontend frameworks against JavaScript frameworks using the JS framework benchmark. He argues that WASM is no longer too slow for DOM-heavy rendering.

On Hacker News

Cited as evidence that DOM access is not the bottleneck for WebAssembly, and as an explanation of signals-based updates versus virtual DOM.

Recommended by 2 HN people across 2 months · HN mentions 2023–2026

Topics

Search by tags

What people said

theironhammer · 2023-07 · Recommendation

[VIDEO] This video might be helpful. Leptos uses Signals, borrowing ideas from SolidJS to update the DOM. There's no VirtualDOM like React. Svelte also doesn't use a VDOM. When there's a state change React has to rerender the entire VDOM tree and the diff it with the real DOM, whereas using the Signals model those frameworks make the change directly in the real DOM. I'm not sure how Svelte manipulates the DOM exactly but I it's similar to how it's done with Frameworks that use Signals such as Leptos and SolidJS. I would say Developer velocity is key if you're a developer. Svelte is a big winner here as it's mental model is easier to understand than React's.

Read the original HN comment ↗
pdpi · 2023-04 · Recommendation

Greg Johnston, author of the Leptos framework, did a pretty good video about this a few weeks ago[0]. The TLDR is (of course): it depends. WASM has no native access to the DOM, so all DOM manipulations from wasm-land have to go through JS bindings with all the (de)serialisation costs that go with crossing the language boundary. That eats up a lot of whatever performance gains you'd see from rust-on-wasm for pure compute. 0. [VIDEO]

Read the original HN comment ↗
tcfhgj · 2026-03 · Reference

> no DOM access meant the only viable use cases were compute-heavy workloads like codecs and crypto, no, it didn't mean that, because the overhead is not a deal breaker: 1) you don't have to do the glue code (libs can do it for you) 2) there's overhead due to glue, but the overhead is so small that WASM web frameworks easily can compete with fast JS frameworks in DOM heavy scenarios. Source: Analysis of the creator of Leptos (a web framework based on WASM): [VIDEO]

Read the original HN comment ↗

Sources

Video by Greg Johnston, played through YouTube.

Data and selection notes

HN summaries and labels may contain AI errors. HN dates refer to discussions, not video publication.

HN Library: HackerTube export (2026-10-31) and open-index/hacker-news. Upstream summaries and classifications may contain AI errors.

Views, duration and playback status refresh separately from the published catalog. When an update fails, existing data remains visible.

Selection checks
  • SaaS & AI candidates: Topic keywords do not match
  • Editor-approved picks: Editorial review is required

Rule matches identify candidates. They do not guarantee video quality or financial results.

About the library and its sources