FLUX 3 Video
FLUX 3 video, with sound
FLUX 3 is Black Forest Labs' video model. Root runs it in the Root app, by API, and from Claude and ChatGPT: clips up to 20 seconds in HD or Full HD, with sound, from a prompt or an image. A 5-second HD clip is $0.98.
Updated
First month free on the Beginner plan, with 650 credits to try any model.
AI video made in Root
What FLUX 3 Video can do
- Clips from 5 to 20 seconds in one run.
- HD and Full HD output, in 21:9, 2:1, 16:9, 4:3, 1:1, 3:4 and 9:16.
- Sound made with the picture, including dialogue. It's on unless you turn it off.
- Start from a prompt alone, or from an image as the first frame.
- Give it up to 4 more frames after the first, and it moves through them in the order you set.
FLUX 3 Video prices
What one clip costs on Root, in dollars, with sound on or off: sound does not change the price. 100 credits is $1.
| Length | HD | Full HD |
|---|---|---|
| 5 s | $0.98 | $1.67 |
| 10 s | $1.96 | $3.34 |
| 15 s | $2.94 | $5.01 |
| 20 s | $3.91 | $6.67 |
A clip shorter than 5 seconds is made, and priced, at 5 seconds.
How to make a FLUX 3 clip in Root
- Add FLUX 3 Video to a project. Open a project, add a Video Gen node and choose FLUX 3 Video. Leave the image inputs empty to work from the prompt alone.
- Wire in up to five frames. Wire in the image the shot opens on, then up to four more frames. The clip moves through them in the order you wire them.
- Write the shot and its sound, then run it. Say what happens, then the line of dialogue and the sounds around it. Pick 5 to 20 seconds, in HD or Full HD, and turn sound off if you only want the picture. The price shows before you run it.
The FLUX 3 Video API
Send the model id flux-3-video. This asks for a ten-second Full HD clip with sound:
curl https://root.film/api/v1/generations \
-H "Authorization: Bearer rfk_your_key" \
-H "Content-Type: application/json" \
-d '{"model":"flux-3-video","project_id":"YOUR_PROJECT_ID",
"input":{"prompt":"a street drummer under a bridge at night, rain on the cymbals, slow push in",
"duration_seconds":10,
"resolution":"fhd"}}'- Add "audio": false for a clip without sound, and image_url to start from an image.
- Make an API key in Root under Settings, then API, and choose a daily spending limit for it.
- The finished file is saved to the project you name, so your team sees it in the app too.
- Send an Idempotency-Key header and a retry never charges twice.
Related guides
FLUX 3 questions
How much does FLUX 3 cost?
On Root, a 5-second FLUX 3 Video clip in HD is $0.98. The longest clip, 20 seconds in Full HD, is $6.67. Sound does not change the price. The price shows before every run.
What is FLUX 3?
FLUX 3 is Black Forest Labs' video model. Root runs it as FLUX 3 Video: it makes clips with sound from a prompt or from images, up to 20 seconds long.
Is FLUX 3 an image model?
On Root, FLUX 3 is the video model. For FLUX stills, Root runs FLUX.2 [max] and FLUX.2 [pro].
How long can a FLUX 3 clip be?
Up to 20 seconds in one run, and at least 5. For a longer scene, make several clips and cut them together on Root's timeline.
Does FLUX 3 make sound?
Yes. It makes the sound with the picture, including dialogue, and sound is on unless you turn it off. It costs the same either way.
Can I use FLUX 3 by API or from Claude?
Yes. Send the model id flux-3-video to Root's API, or connect Root to Claude or ChatGPT and ask for a FLUX 3 clip in the chat. It's priced and saved to your project the same way as in the app.
Can I try FLUX 3 for free?
For a month, yes. The first month of Root's Beginner plan is free and comes with 650 credits, enough for six FLUX 3 Video clips of five seconds in HD. After that the plan is $9 a month, and you can cancel whenever you like.
Try Root free for a month
The first month of the Beginner plan is free and comes with 650 credits to spend on any model. After that it's $9 a month, and you can cancel whenever you like.