# Lovable — Faster previews, soon powered by OJ

- Company: Lovable (lovable.dev)
- Announced: 2026-09-15T09:00:00+00:00
- Category: capability-change
- Coverage: not counted
- Announcement: yes
- Group: announcements
- Source: https://lovable.dev/blog/faster-previews-oj
- Record: https://forck.live/items/12052-faster-previews-soon-powered-by-oj
- Subject: Lovable / AI app builder

Lovable is rolling out OJ, a Rust-based preview engine, to replace Vite for its preview sandboxes. OJ reduces cold start times by roughly 4x on a synthetic benchmark and memory usage from gigabytes to hundreds of megabytes, cutting median preview load time from 17.4s to 8.0s in production. The engine is designed to run existing Vite configs and plugins unchanged, and is being deployed gradually across previews.

## Evidence

Verbatim from https://lovable.dev/blog/faster-previews-oj:

> Total load roughly halved. The time from opening a preview to a usable app dropped from 17.4s to 8.0s at the median. Sandboxes ready almost 5x faster. Sandbox acquisition fell from 14.5s to 3.0s at the median, a direct payoff of the lighter OJ image.

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Record: https://forck.live/items/12052-faster-previews-soon-powered-by-oj
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