Preview and Exports
Play the build, check the numbers, and download the file.
The preview panel sits beside the chat and runs your actual composition — not a rendered video file. That is why it appears within seconds of a build finishing and why scrubbing is instant.
Preview states
The status chip tells you what is happening:
| State | Meaning |
|---|---|
| Booting | An isolated sandbox is starting up. Normal on a cold project. |
| Live | The composition is running. Play, scrub, and iterate. |
| Updating | A follow-up build is being applied. The current version keeps playing until the new one is ready. |
Booting takes longest the first time you open a project in a while. If it stalls, see Troubleshooting.
Composition stats
While the preview is live, the header shows three numbers pulled from the composition itself:
| Stat | What it means |
|---|---|
| Duration | Total length |
| FPS | Frame rate, usually 30 |
| Resolution | Output size, labeled 720p / 1080p / 1440p / 4K when it matches |
These are worth a glance before every export. They are the fastest way to catch a build that quietly drifted to a different length or aspect ratio than you asked for.
These are not export settings
Duration, frame rate, and aspect ratio belong to the composition, so you change them in chat — "make it 20 seconds", "switch to 9:16" — not in the export dialog. The dialog only chooses format, quality, and file name.
Aspect ratios
State the target platform or the ratio in your brief:
| Ratio | Typical use |
|---|---|
| 16:9 | YouTube, landing pages, presentations |
| 9:16 | TikTok, Reels, Shorts, Stories |
| 1:1 | Feed posts, logo stings, square ads |
To ship one idea in several ratios, see Multi-Format Cuts.
Motion quality notes
A Motion quality notes banner sometimes appears above the preview. These are advisory observations — pacing, a scene that could move more — and they never block a build. Read them, act on the ones you agree with, and dismiss the banner.
Hard failures are handled differently: fluos repairs them automatically, and for narrated explainers it will refuse to publish a version whose scenes are measurably frozen rather than hand you a slideshow. See Build Mode.
Exporting
Press Download to open the export dialog.
Format
| Format | Best for | Notes |
|---|---|---|
| MP4 | Anything final — ads, social, embeds | Includes narration, music, and sound effects |
| GIF | Short silent loops, email and chat | No audio, and often a larger file than the MP4 |
Quality
| Quality | Tradeoff |
|---|---|
| High | Best result, slowest render — the default |
| Standard | Balanced |
| Draft | Fastest — good for checking timing before committing to a final render |
You can also set the download file name here.
While it renders
Rendering happens on a server, not in your browser, and shows live progress. Compositions with embedded video take longest.
Draft first on long videos
For anything over about 30 seconds, export a Draft to sanity-check pacing and the end card, then re-export at High. It is much faster than discovering a timing problem after a full-quality render.
After the export
Exports are saved to the project and downloaded through your browser. Access follows project permissions, so a download link is not usable by someone outside the workspace.
If an export fails, the message explains why. The most common cause is a composition that is too heavy to render inside the time budget — long embedded footage is usually the culprit. Shorten the segment or reduce scope and try again.