## Problem HyperFrames already had `--gpu`, but that flag only controlled FFmpeg hardware encoding. The browser capture path still forced Chrome/WebGL through SwiftShader software GL via `--use-angle=swiftshader`, so WebGL-heavy local renders could leave the biggest bottleneck on the CPU path. That made the existing flag naming easy to misread: `--gpu` sounded like it accelerated the whole render, but it did not change the browser frame-capture backend. ## What this fixes - Enables host browser GPU acceleration automatically for local CLI renders. - Adds `--no-browser-gpu` as the local opt-out for software Chrome/WebGL capture. - Keeps `--browser-gpu` as an explicit local browser-GPU request. - Adds `browserGpuMode: "software" | "hardware"` to engine config, with `PRODUCER_BROWSER_GPU_MODE` env support for lower-level producer users. - Keeps Docker browser capture on the deterministic software path. - Maps hardware browser GPU mode to platform-native Chrome backends: - macOS: Metal-backed ANGLE - Windows: D3D11-backed ANGLE - Linux: EGL - Blocks explicit `--browser-gpu --docker` with a clear error because Docker browser GPU passthrough is not cross-platform. - Clarifies docs so `--gpu` means FFmpeg encoder GPU and browser GPU means Chrome/WebGL capture GPU. - Keeps encoder backend selection auto-detected from FFmpeg capabilities: - NVIDIA: NVENC - macOS: VideoToolbox - Linux: VAAPI - Intel: QSV ## Why two flags There are two separate GPU surfaces in the render pipeline: 1. Browser GPU controls Chrome frame capture. - Affects WebGL, canvas, CSS rendering, compositing, and screenshot capture inside the browser. - This is enabled automatically for local CLI renders. - Use `--no-browser-gpu` when you want the software browser baseline. 2. `--gpu` controls FFmpeg video encoding. - Affects the final encode step after frames have already been captured. - The concrete encoder is auto-detected from the host FFmpeg build and hardware. - It can be faster for some machines/codecs, but it is not equivalent to browser rendering acceleration. The controls stay independent because users may want: - `hyperframes render` for the fast local default with browser GPU capture. - `hyperframes render --no-browser-gpu` for the software-browser local baseline. - `hyperframes render --gpu` for browser GPU capture plus hardware FFmpeg encoding. - `hyperframes render --no-browser-gpu --gpu` for software browser capture plus hardware FFmpeg encoding. - `hyperframes render --docker` for deterministic browser capture. ## Why `--gpu` does not imply browser GPU Keeping `--gpu` scoped to FFmpeg encoding avoids a semantic break and keeps the risk profile explicit: - `--gpu` already means encoder acceleration. Expanding it to also change Chrome capture would silently alter behavior for users who only wanted hardware encoding. - Browser GPU and encoder GPU have different portability. Encoder GPU can work in Docker when the host exposes the right devices; browser GPU passthrough is not cross-platform, so this PR intentionally blocks explicit `--browser-gpu --docker`. - The Apple presentation benchmark shows why the controls should stay separate: browser GPU capture was the useful improvement, while macOS VideoToolbox via `--gpu` was slower and produced larger output for this `standard` H.264 run. If HyperFrames later wants a single umbrella acceleration control, it should be explicit, for example `--acceleration browser|encoder|all` or `--gpu=browser|encoder|all`, rather than changing the meaning of the existing boolean `--gpu`. ## Root cause `buildChromeArgs()` always injected `--use-gl=angle --use-angle=swiftshader`. `disableGpu` only appended `--disable-gpu`; it did not provide a hardware-GPU mode. That made the public `--gpu` flag look broader than it was, because render capture stayed software-backed even when encoder GPU was requested. ## Verification ### Local checks - `bun install` - `bun run build:hyperframes-runtime` - `bun run --filter @hyperframes/engine test src/config.test.ts src/services/browserManager.test.ts` - `bun run --filter @hyperframes/cli test src/utils/dockerRunArgs.test.ts src/commands/render.test.ts` - `bun run --filter @hyperframes/cli typecheck` - `bun run --filter @hyperframes/engine typecheck` - `bun run --filter @hyperframes/producer typecheck` - `cd packages/producer && bunx vitest run src/services/renderOrchestrator.test.ts` - `bunx oxlint packages/cli/src/commands/render.ts packages/cli/src/commands/render.test.ts packages/cli/src/utils/dockerRunArgs.ts packages/cli/src/utils/dockerRunArgs.test.ts packages/engine/src/config.ts packages/engine/src/config.test.ts packages/engine/src/services/browserManager.ts packages/engine/src/services/browserManager.test.ts packages/producer/src/services/renderOrchestrator.test.ts` - `bunx oxfmt --check ...` on changed source/docs files - `git diff --check` - `bun packages/cli/src/cli.ts render --help | rg -n "browser-gpu|no-browser-gpu|GPU"` - `bun packages/cli/src/cli.ts render packages/producer/tests/css-spinner-render-compat/src --output /tmp/hf-auto-browser-gpu-smoke.mp4 --workers 1 --quality draft --fps 24 --strict` - Render plan prints `GPU: browser GPU (auto)`. - `bun packages/cli/src/cli.ts render packages/producer/tests/css-spinner-render-compat/src --no-browser-gpu --output /tmp/hf-software-browser-gpu-smoke.mp4 --workers 1 --quality draft --fps 24 --strict` - Render plan does not print browser GPU. - `bun packages/cli/src/cli.ts render packages/producer/tests/css-spinner-render-compat/src --docker --browser-gpu --output /tmp/should-not-render.mp4` - Exits 1 with `Browser GPU is local-only`. - `buildDockerRunArgs()` regression coverage asserts Docker container args include `--no-browser-gpu`, preventing nested container renders from re-enabling browser GPU through the local CLI default. - `resolveBrowserGpuForCli()` regression coverage asserts `PRODUCER_BROWSER_GPU_MODE=software` opts out when no CLI browser-GPU flag is supplied, while explicit `--browser-gpu` / `--no-browser-gpu` still win. - `ffmpeg -v error -i /tmp/hf-auto-browser-gpu-smoke.mp4 -f null -` - `ffmpeg -v error -i /tmp/hf-software-browser-gpu-smoke.mp4 -f null -` - `ffprobe -v error -show_entries format=duration:stream=codec_name,width,height,r_frame_rate -of json /tmp/hf-browser-gpu-smoke.mp4` -> H.264, 1920x1080, 24fps, 5.0s ### Apple presentation benchmark Rendered `/Users/miguel07code/Downloads/apple-presentation.zip` as supplied after extracting to `/tmp/hf-apple-profile/apple-presentation`. Fixed settings: - 1920x1080 - 30fps - `standard` quality - 4240 frames - 141.32s duration - 8-worker cap; render auto-calibration used 6 capture workers - macOS host detected FFmpeg GPU encoder: `videotoolbox` | Mode | Equivalent flags after this PR | Wall time | vs software-browser baseline | Speed | Capture | Encode | Output | | --- | --- | ---: | ---: | ---: | ---: | ---: | ---: | | Software browser + CPU encode | `--no-browser-gpu` | 120.77s | baseline | 1.17x | 97.87s | 10.04s | 8.38MB | | Browser GPU + CPU encode | default local render | 70.10s | 42.0% faster | 2.02x | 50.72s | 9.91s | 8.39MB | | Software browser + encoder GPU | `--no-browser-gpu --gpu` | 133.16s | 10.3% slower | 1.06x | 103.58s | 18.31s | 25.43MB | | Browser GPU + encoder GPU | `--gpu` | 74.12s | 38.6% faster | 1.91x | 46.69s | 17.93s | 25.45MB | Result: browser GPU capture is the meaningful improvement for this WebGL/browser-capture-heavy presentation. VideoToolbox encoding was slower and produced larger files for this current `standard` H.264 path, so `--gpu` should stay separate and opt-in. Why `--gpu` plus browser GPU was slower than browser GPU alone: the combined run captured about 4.0s faster than browser GPU alone, but VideoToolbox encoding was about 8.0s slower than CPU x264 encoding, so the encode loss outweighed the capture gain. ### VideoToolbox flag check I also isolated the encode stage against the already-captured Apple frames to check whether macOS GPU encoding only needed special flags. `ffmpeg -h encoder=h264_videotoolbox` does not expose a CRF/CQ-style quality option like x264. It exposes bitrate-oriented and VideoToolbox-specific options such as `-b:v`, `-realtime`, `-profile`, `-coder`, `-prio_speed`, `-power_efficient`, and `-allow_sw`. That means our current `-q:v` mapping is not equivalent to x264 CRF and can produce very different bitrate/size behavior. Measured full-frame encode variants on this host: | VideoToolbox variant | Encode wall time | Output size | Bitrate | | --- | ---: | ---: | ---: | | Current `-q:v 64 -allow_sw 1` | 18.76s | 25.31MB | 1.43 Mbps | | Current without `-allow_sw 1` | 18.21s | 25.31MB | 1.43 Mbps | | `-b:v 500k -maxrate 750k -bufsize 1000k -profile high -coder cabac -realtime 1 -prio_speed 1 -power_efficient 0` | 20.58s | 7.42MB | 0.42 Mbps | | Same with `-b:v 1500k` | 20.84s | 16.70MB | 0.95 Mbps | | `-b:v 500k -profile baseline -coder cavlc -realtime 1 -prio_speed 1 -power_efficient 0` | 18.11s | 8.94MB | 0.51 Mbps | Conclusion: VideoToolbox can be made size/bitrate-predictable with explicit `--video-bitrate`, but the tested speed-oriented flags did not make it faster than CPU x264 wall time for this render. That reinforces keeping `--gpu` encoder acceleration explicit and separate from browser GPU capture. Artifacts from the local benchmark: - `/tmp/hf-apple-profile/results/cpu.mp4` - `/tmp/hf-apple-profile/results/browser-gpu.mp4` - `/tmp/hf-apple-profile/results/encoder-gpu.mp4` - `/tmp/hf-apple-profile/results/full-gpu.mp4` - `/tmp/hf-apple-profile/results/summary.json` All four benchmark MP4s completed `ffprobe` and full `ffmpeg -f null` decode checks. ### Pixel comparison Compared decoded MP4 output between software-browser and browser-GPU renders: - Apple presentation: - 4240 frames compared - 636 exact matching decoded frame hashes - 3604 different decoded frame hashes - Average PSNR: 57.79 dB - `css-spinner-render-compat` clean fixture: - 120 frames compared - 0 exact matching decoded frame hashes - Average PSNR: 61.57 dB Interpretation: browser GPU output is not strict hash/pixel-identical to the software-browser path after lossy H.264 encode, but the measured deltas are visually tiny. Above 50 dB PSNR is typically visually indistinguishable for normal video review. Use `--no-browser-gpu` or Docker when strict cross-run/cross-machine reproducibility matters more than local speed. ### Browser verification - Started HyperFrames Studio preview for `packages/producer/tests/css-spinner-render-compat/src`. - Used `agent-browser` to open `http://localhost:5191#project/src` and verify the composition loaded in Studio. - Screenshots: - `/tmp/hf-gpu-browser-proof/preview-loaded.png` - `/tmp/hf-gpu-browser-proof/preview-playing.png` - `/tmp/hf-gpu-browser-proof/preview-frame-60.png` - Agent-browser recordings: - `/tmp/hf-gpu-browser-proof/preview-playback.webm` - `/tmp/hf-gpu-browser-proof/preview-seek.webm` ## Notes - Browser GPU is enabled automatically for local CLI renders and disabled in Docker. - `--no-browser-gpu` is the opt-out for software Chrome/WebGL capture. - `--gpu` remains encoder-only and opt-in. - The Apple presentation zip has existing lint errors around unmanaged nested videos and imperative media `play()` calls. The benchmark still compares the same supplied source across modes, but it should not be treated as a clean deterministic-composition fixture.
Write HTML. Render video. Built for agents.
Hyperframes is an open-source video rendering framework that lets you create, preview, and render HTML-based video compositions — with first-class support for AI agents.
Quick Start
Option 1: With an AI coding agent (recommended)
Install the HyperFrames skills, then describe the video you want:
npx skills add heygen-com/hyperframes
This teaches your agent (Claude Code, Cursor, Gemini CLI, Codex) how to write correct compositions and GSAP animations. In Claude Code, the skills register as slash commands — invoke /hyperframes to author compositions, /hyperframes-cli for CLI commands, and /gsap for animation help.
For Claude Design, open docs/guides/claude-design-hyperframes.md on GitHub and click the download button (↓) to save it, then attach the file to your Claude Design chat. It produces a valid first draft; refine in any AI coding agent. See the Claude Design guide.
For Codex specifically, the same skills are also exposed as an OpenAI Codex plugin — sparse-install just the plugin surface:
codex plugin marketplace add heygen-com/hyperframes --sparse .codex-plugin --sparse skills --sparse assets
For Claude Code, the repo also ships a Claude Code plugin manifest: test it locally with claude --plugin-dir .. The manifest intentionally omits skills because Claude Code auto-discovers the root skills/ directory by convention, and for marketplace submission use the title HyperFrames by HeyGen plus the black/white icon assets at assets/claude-code-icon-dark.svg and assets/claude-code-icon-light.svg for the two theme slots.
For Cursor, the same skills are packaged as a Cursor plugin — install from the Cursor Marketplace, or sideload by cloning this repo and pointing Settings → Plugins → Load unpacked at the repo root.
Try it: example prompts
Copy any of these into your agent to get started. The /hyperframes prefix loads the skill context explicitly so you get correct output the first time.
Cold start — describe what you want:
Using
/hyperframes, create a 10-second product intro with a fade-in title, a background video, and background music.
Warm start — turn existing context into a video:
Take a look at this GitHub repo https://github.com/heygen-com/hyperframes and explain its uses and architecture to me using
/hyperframes.
Summarize the attached PDF into a 45-second pitch video using
/hyperframes.
Turn this CSV into an animated bar chart race using
/hyperframes.
Format-specific:
Make a 9:16 TikTok-style hook video about [topic] using
/hyperframes, with bouncy captions synced to a TTS narration.
Iterate — talk to the agent like a video editor:
Make the title 2x bigger, swap to dark mode, and add a fade-out at the end.
Add a lower third at 0:03 with my name and title.
The agent handles scaffolding, animation, and rendering. See the prompting guide for more patterns.
Option 2: Start a project manually
npx hyperframes init my-video
cd my-video
npx hyperframes preview # preview in browser (live reload)
npx hyperframes render # render to MP4
hyperframes init installs skills automatically, so you can hand off to your AI agent at any point.
Requirements: Node.js >= 22, FFmpeg
Why Hyperframes?
- HTML-native — compositions are HTML files with data attributes. No React, no proprietary DSL.
- AI-first — agents already speak HTML. The CLI is non-interactive by default, designed for agent-driven workflows.
- Deterministic rendering — same input = identical output. Built for automated pipelines.
- Frame Adapter pattern — bring your own animation runtime (GSAP, Lottie, CSS, Three.js).
Hyperframes vs Remotion
Hyperframes is inspired by Remotion — we used Remotion at HeyGen in production, learned a ton from it, and kept attribution comments in the source for the patterns it pioneered (Chrome launch flags, image2pipe → FFmpeg streaming, frame buffering). Both tools drive headless Chrome and both are deterministic. They differ on one decision: what the primary author writes. Remotion's bet is React components; Hyperframes' bet is HTML.
| Hyperframes | Remotion | |
|---|---|---|
| Authoring | HTML + CSS + GSAP | React components (TSX) |
| Build step | None; index.html plays as-is |
Required (bundler) |
| Library-clock animations (GSAP, Anime.js, Motion One) | Seekable, frame-accurate | Plays at wall-clock during render |
| Arbitrary HTML / CSS passthrough | Paste and animate | Rewrite as JSX |
| Distributed rendering | Single-machine today | Lambda, production-ready |
Licensing: fully open source vs source-available
Hyperframes is completely open source under Apache 2.0 — an OSI-approved license. Use it commercially at any scale, with no per-render fees, no seat caps, no company-size thresholds.
Remotion is source-available, not open source. The code is on GitHub under a custom Remotion License that requires a paid company license above small-team thresholds. It's a great product with a real team behind it — but if open-source licensing matters to you (OSI compliance, redistribution rights, no per-use fees), that's a first-order decision point.
Full write-up with benchmarks, an honest list of where each tool wins, and a GSAP side-by-side: Hyperframes vs Remotion guide.
How It Works
Define your video as HTML with data attributes:
<div id="stage" data-composition-id="my-video" data-start="0" data-width="1920" data-height="1080">
<video
id="clip-1"
data-start="0"
data-duration="5"
data-track-index="0"
src="intro.mp4"
muted
playsinline
></video>
<img
id="overlay"
class="clip"
data-start="2"
data-duration="3"
data-track-index="1"
src="logo.png"
/>
<audio
id="bg-music"
data-start="0"
data-duration="9"
data-track-index="2"
data-volume="0.5"
src="music.wav"
></audio>
</div>
Preview instantly in the browser. Render to MP4 locally or in Docker.
Catalog
50+ ready-to-use blocks and components — social overlays, shader transitions, data visualizations, and cinematic effects:
npx hyperframes add flash-through-white # shader transition
npx hyperframes add instagram-follow # social overlay
npx hyperframes add data-chart # animated chart
Browse the full catalog at hyperframes.heygen.com/catalog.
Documentation
Full documentation at hyperframes.heygen.com/introduction — Quickstart | Guides | API Reference | Catalog
Packages
| Package | Description |
|---|---|
hyperframes |
CLI — create, preview, lint, and render compositions |
@hyperframes/core |
Types, parsers, generators, linter, runtime, frame adapters |
@hyperframes/engine |
Seekable page-to-video capture engine (Puppeteer + FFmpeg) |
@hyperframes/producer |
Full rendering pipeline (capture + encode + audio mix) |
@hyperframes/studio |
Browser-based composition editor UI |
@hyperframes/player |
Embeddable <hyperframes-player> web component |
@hyperframes/shader-transitions |
WebGL shader transitions for compositions |
Skills
HyperFrames ships skills that teach AI agents framework-specific patterns that generic docs don't cover.
npx skills add heygen-com/hyperframes
| Skill | What it teaches |
|---|---|
hyperframes |
HTML composition authoring, captions, TTS, audio-reactive animation, transitions |
hyperframes-cli |
CLI commands: init, lint, preview, render, transcribe, tts, doctor |
hyperframes-registry |
Block and component installation via hyperframes add |
website-to-hyperframes |
Capture a URL and turn it into a video — full website-to-video pipeline |
remotion-to-hyperframes |
Translate a Remotion (React) composition into a HyperFrames HTML composition |
gsap |
GSAP animation API, timelines, easing, ScrollTrigger, plugins, React/Vue/Svelte, performance |
Contributing
See CONTRIBUTING.md for guidelines.
Cloning the repo
The repo uses Git LFS for golden regression-test baselines under packages/producer/tests/**/output.mp4 (~240 MB of .mp4 files). If you're cloning the full repo for development, install Git LFS first:
# macOS
brew install git-lfs
# Ubuntu/Debian
sudo apt install git-lfs
# Windows
winget install GitHub.GitLFS
# (or install Git for Windows, which bundles Git LFS as an optional component)
# Then (once, per machine)
git lfs install
If you hit git-lfs filter-process: command not found during git clone or npx skills add heygen-com/hyperframes, install Git LFS and retry. You can also skip LFS content if you only need the source files:
GIT_LFS_SKIP_SMUDGE=1 git clone https://github.com/heygen-com/hyperframes.git
