Preview and Exports
Play the build, check the numbers, and download the file.
The preview panel sits beside the chat and plays your actual video as it is built — 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 |
|---|---|
| Building | fluos is creating the video. |
| Booting | Your preview is starting up. Normal on a cold project. |
| Live | The video is ready. 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 about the video 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 video itself, 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.
Scenes
Under the preview, a Scenes strip lists the scenes of your video. Click one to jump to it — and to reference it in chat, so "make this one shorter" knows which scene you mean.
Quick edits
For visual tweaks, point at the preview instead of describing where something is.
- Press Edit on preview above the preview.
- Pause on the moment you want to change.
- Click an element to select it, or drag to draw around an area.
- Type what should change — "What should change about this element?" — or use the microphone to dictate it. Press Enter to send.
The edit goes to the agent with the exact moment and the element or area you marked, so it knows what you mean. Reselect (or Esc) picks a different area, and the X leaves quick edit.
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.
Only errors that break playback are handled differently: fluos repairs them automatically before updating the preview. Visual findings, including frozen scenes, never block an update. See Build Mode.
Exporting
Press Export to open the export dialog, choose your options, and press Start export.
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 |
| WebM | Transparent video for the web | Includes audio and preserves transparent areas |
| MOV / ProRes | Editing masters | ProRes 4444 with audio and transparency; large files |
| PNG sequence | Compositing and frame processing | Lossless transparent frames in a ZIP; no audio |
Transparent formats preserve transparent areas already in your video. Ask the agent to remove a background when needed; selecting a format does not remove it.
Quality
| Quality | Tradeoff |
|---|---|
| High | Best result, slowest render — the default |
| Standard | Balanced |
| Draft | Fastest — good for checking timing before committing to a final render |
Quality choices apply to MP4, GIF, and WebM. MOV uses fixed ProRes 4444 quality; PNG frames are lossless.
You can also set the download file name here.
Advanced options
- Output size: export at the video's own size or a compatible 4K landscape, portrait, or square size. 4K uses SDR and requires a matching aspect ratio and integer scale. Incompatible choices are disabled. GIF stays limited to 720 pixels wide.
- Color range: Automatic, SDR, or HDR for MP4. HDR requires native HDR media and a compatible HEVC player. The finished file is checked; a silent SDR fallback fails with a useful error.
- Template variables: ask the agent to make text or colors reusable variables, then enter a JSON object such as
{"title":"Summer launch"}. Only variables the video declares, with matching types, are accepted. These overrides change the export, not the saved preview or audio. - Batch variants: enter an array such as
[{"title":"Summer"},{"title":"Autumn"}]for up to six sequential downloads with numbered filenames. Keep this tab open. Cancel stops the current render and remaining variants; a failed variant stops the batch. Existing export limits apply. If the video changes, restart the batch. Repeating an unchanged successful variant reuses its export.
Removing a background
Ask the agent to separate a person from a library image or video. Images produce transparent PNGs; videos produce silent transparent WebM clips, up to six seconds at 720 pixels and 15 fps. The original source and audio remain available. The cutout lines up with the original footage and keeps its original audio track. This uses human segmentation; it does not reconstruct scenery hidden behind the person.
While it renders
Rendering happens on our servers, not in your browser, and shows live progress. Videos with embedded footage 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 video 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.