Why we built OFF — a local 4K upscaler for Mac

Upscaling a video shouldn't mean uploading your footage to someone else's servers and paying credits for every clip. Yet that's how most AI upscalers work today: your files leave your machine, you wait in a queue you don't control, and the meter runs the whole time.

We thought the modern Mac deserved better. Apple Silicon is genuinely fast at the kind of neural work upscaling needs, so we built OFF — 4K Upscaler: an app that turns ordinary video and photos into crisp 4K entirely on your Mac.

What it does

• Video to 1080p or 4K. Bring 480p, 720p, and 1080p clips up to sharp 4K with on-device Real-ESRGAN super-resolution, portrait or landscape, any length.
• Keeps your audio. The original music and voice are muxed back into a clean MP4, untouched.
• Photos too. 2×/3×/4× image upscaling with a before/after slider and fine adjustments.
• Batch & queue. Drop one file or a hundred. A floating Now bar shows live progress and ETA, and lets you reorder or remove jobs.
• Private by default. Nothing is uploaded. It works fully offline.

How it works

OFF bundles two excellent open-source tools, Real-ESRGAN for AI super-resolution and FFmpeg for media handling, so it runs on a fresh Mac with nothing to install. The hard part was making long videos finish reliably on modest hardware. We use a segmented pipeline (extract → upscale → encode per chunk) and RAM-aware tiling so it stays within memory and doesn't stall, even on an 8 GB M2 Air. It also estimates the disk space a 4K job needs up front and keeps a safety buffer.

Free for the first 100,000

We want OFF in as many hands as possible, so the first 100,000 people get lifetime free access. No subscription, no per-video credits. It's our thank-you for trying something new early.

What's next

We're working on an optional Pro tier with AI features layered on top of upscaling, things like AI voiceover, narration, and audio cleanup. The core local upscaling stays the heart of the app; Pro is for people who want the extra AI tooling.

Try it

OFF is a native macOS app for Apple Silicon. We'd love your feedback, especially on quality and performance with your own footage.

Questions or feedback? support@off.onl · off.onl