Render farm of one: batch-rendering Remotion videos locally with Bun
Batch-render many Remotion videos on your own Mac, one template, a list of data, and the Bun runtime turn your laptop into a render farm of one, for free.
You can batch-render dozens of Remotion videos on your own Mac — one template, a list of data, and the Bun runtime turning your laptop into a render farm of one. Because Remotion is programmatic video, a single scene template plus an array of inputs (episode titles, changelog entries, localized text) renders a distinct, exact MP4 for each. ReDock runs Remotion on the Bun runtime as a one-click stack with live frame progress, so batch rendering happens locally, free, with no cloud render service and no per-minute bill.
What “render farm of one” means
Cloud video platforms sell rendering by the minute because a single machine, they assume, is too slow to do volume. But most template-based video — intros, data cards, localized variants, per-feature demos — is short and cheap to draw. A modern Mac renders these comfortably. When your videos come from one template fed by a list, “batch rendering” is just a loop: for each item in the list, render the template with that item’s data.
That’s the whole idea. You’re not editing fifty videos; you’re rendering one template fifty times with different inputs. The renderer draws each frame exactly from the data, so every output is consistent and correct — the programmatic-video property explained in free AI video with Remotion.
Why Bun matters here
ReDock runs Remotion on the Bun runtime. Bun is a fast JavaScript runtime, and for a batch job — spinning up the render, walking frames, encoding, and moving to the next item — a quick runtime keeps the loop tight. ReDock warm-starts it, so you’re not paying startup cost on every video, and it shows live frame progress so you can watch the batch advance instead of guessing whether it’s stuck.
ReDock — a free (alpha) native macOS app — handles the runtime, the real https://something.test preview URL, and the process management. No terminal, no manual bun install. The stack details are in the stacks reference and setup in the install guide.
Building a batch
The pattern is straightforward:
- One template. A Remotion scene that takes its content as props — title, colors, images, timing. Build it once; the Remotion tutorial covers the basics.
- A list of inputs. An array of data objects — one per video. This might be your changelog, a list of episodes, or a set of localized strings.
- A render loop. For each input, render the template with those props to a named MP4. The Bun runtime does the drawing and encoding.
- Collect the outputs. A folder of finished videos, each exact and on-brand.
Common batch jobs: a season of YouTube intros, a video per changelog entry (see auto-generate product demo videos), or localized versions of one announcement.
Let an agent drive the batch
Because ReDock exposes its whole app as MCP tools on localhost:47200, an agent can orchestrate the batch: read your list, render each item, and report progress. Point Claude, Cursor, or ReDock’s built-in agent at the template and the data. With ReDock’s local-LLM catalog, this needs no API keys — the model runs on your Mac. The agent can also write the template to begin with, as in Claude-written Remotion scenes.
Local, free, and honest about limits
Everything stays on your machine: your assets, your data, your renders, at zero marginal cost. There’s no render queue you wait in behind other customers and no per-video fee. This is the video half of the zero-dollar creator stack.
Two honest limits. First, a batch is bounded by your Mac’s speed — a hundred long, complex videos will take real wall-clock time, and your machine works while it renders. For most template batches (short clips, dozens of items) that’s minutes, not hours. Second, this is local rendering, so your Mac needs to be awake and ReDock running for the batch to finish. For the volumes a solo creator or small team actually needs, a render farm of one is plenty.
FAQ
How many videos can I render at once?
As many as your list has — the limit is your Mac’s time, not a quota. Short template-based clips render quickly; a large batch of long, complex videos takes proportionally longer. ReDock shows live frame progress throughout.
Why Bun instead of Node?
ReDock runs Remotion on the Bun runtime, a fast JavaScript runtime that keeps the render loop tight and warm-starts so you skip repeated startup cost. You don’t configure it — ReDock manages the runtime.
Do I need a cloud render service?
No. The point is local rendering — your Mac is the render farm. No queue, no per-minute billing, and your assets never leave your machine.
Your laptop is a capable render farm — one template, a list, and Bun. Download ReDock and render your first batch today.