FLUX 3 Video vs Gen-4.5

Pick FLUX 3 Video when…

• You are generating in volume and the 3-credit difference per clip adds up fast
• You have settled on the shot and are rendering the version that ships
• The clip ships as-is and needs its own synchronized sound
• You need the higher ceiling — up to FHD output
• The brief leans on synchronized audio

Trade-off: You wait 10s longer per clip.

Pick Gen-4.5 when…

• The clip is a final deliverable and 3 extra credits per render is not the constraint
• You are still exploring and need a tight generate-judge-regenerate loop (~90s / 5s clip versus ~100s / 5s clip)
• You are scoring the piece properly and would discard generated audio anyway
• The brief leans on text & image to video

Trade-off: You pay 3 more credits on every generation; You will handle audio in post.

Vendor angle

These come from different vendors — Black Forest Labs and RunwayML — which is where the interesting differences live. Vendors train on different data and optimise for different failure modes, so the same prompt can produce recognisably different motion, grain and lighting. On FlowAIVideo both sit behind one account and one balance, so you never have to pick a vendor before you have seen the output.

What it costs to decide

Running one clip on each costs 153 credits in total (75 + 78). A new account starts with 40 free credits, which covers FLUX 3 Video plus part of the other — enough to run a real comparison rather than reading about one. Paid plans start at 600 credits per month, and there is no per-model subscription: one balance, 22 models.