seedance-2-0

Seedance 2.0 (ByteDance)

Seedance 2.0 is the ByteDance Seed team's unified multimodal video+audio model (released Feb 2026, globally available via partner APIs April 2026). It is the preferred premium default for cinematic, trailer, teaser, and motion-led work inside OpenMontage whenever any supporting gateway is configured. OpenMontage wraps four gateways directly (seedance_video → fal.ai, seedance_replicate → Replicate, runway_video with model="seedance_2.0" → Runway, higgsfield_video with model="seedance_2.0" → Higgsfield); BytePlus / Freepik / HeyGen-Video-Agent wrappers are on the roadmap. The scoring engine deduplicates by provider="seedance" so whichever gateway the user has configured wins automatically — agents should pass preferred_provider="seedance" to video_selector (or let the scorer pick) rather than routing to a specific gateway by name.

Why it is the OpenMontage premium default

Capability	Seedance 2.0	Notes
Single-pass native synced audio	Yes	Speech + SFX + ambience generated jointly, not post-sync
Multi-shot inside one generation	Yes	Multiple cuts/shots in a single prompt
Director-level camera control	Yes	Camera language (dolly, tilt, arc, crane, handheld) honored
Lip-sync from quoted dialogue	Yes	Character says: "..." matches mouth shapes
Reference conditioning	Up to 9 images + 3 video clips + 3 audio clips	12-asset multimodal
Character identity consistency	Yes	Face/subject stable across shots
Max shot duration	15 s	auto / 4–15 s
Resolution ceiling	1080p on some endpoints (720p default on fal.ai)	Provider-dependent
Elo (Artificial Analysis)	1269 (#1 as of Feb 2026)	Beat Veo 3, Sora 2, Runway Gen-4.5

Switch away only for a specific reason: strict budget (use the fast variant or LTX), user-preferred provider (VEO/Sora/Kling), or a stylistic fit that favors another model.

Provider surfaces

Surface	Env	OpenMontage tool	Status	Notes
fal.ai (primary)	FAL_KEY	seedance_video	✅ wrapped	Model IDs below. Supports T2V, I2V, reference-to-video; standard and fast variants. Default in OpenMontage.
Replicate	REPLICATE_API_TOKEN	seedance_replicate	✅ wrapped	bytedance/seedance-2.0 + bytedance/seedance-2.0-fast. Standard Replicate prediction API.
Runway	RUNWAY_API_KEY	runway_video (model: seedance_2.0)	✅ wrapped	Third-party Seedance 2.0 model inside Runway. Unlimited/Enterprise plans, non-US only. Selected via model param.
Higgsfield	HIGGSFIELD_API_KEY + _SECRET	higgsfield_video (model: seedance_2.0)	✅ wrapped	Seedance 2.0 is the default model on this tool. Emphasis on character identity + long-form chaining.
HeyGen	HEYGEN_API_KEY	heygen_video (1.x only) + TODO	⚠️ 1.x only	The seedance_pro / seedance_lite workflow provider strings on HeyGen map to Seedance 1.x. 2.0 access flows through Video Agent / Avatar Shots endpoints — a separate seedance_heygen tool is on the roadmap.
BytePlus ModelArk / Volcengine	BytePlus token	not wrapped	🔜 roadmap	Direct from ByteDance. Pro ~$0.15 / 5 s, Lite ~$0.010/s. Token-based.
Freepik	Freepik token	not wrapped	🔜 roadmap	POST /v1/ai/image-to-video/seedance-pro-1080p for 1080p I2V
Pollo / PiAPI / Atlas Cloud / AIMLAPI	various	not wrapped	🔜 roadmap	Aggregators resell fal.ai or ByteDance endpoints

fal.ai model IDs (used by seedance_video)

bytedance/seedance-2.0/text-to-video
bytedance/seedance-2.0/image-to-video
bytedance/seedance-2.0/reference-to-video        # 9 img + 3 vid + 3 audio
bytedance/seedance-2.0/fast/text-to-video
bytedance/seedance-2.0/fast/image-to-video
bytedance/seedance-2.0/fast/reference-to-video

Pricing (fal.ai, 720p): standard $0.3034 / s (T2V), $0.3024 / s (I2V). Fast $0.2419 / s across endpoints. The fast variant trades some camera/motion fidelity for latency and cost — do not route slow-mo, multi-shot, or dolly-heavy prompts to fast on the first try.

Calling Seedance 2.0 inside OpenMontage

Always go through video_selector with preferred_provider="seedance" (or let the scoring engine pick it):

from tools.tool_registry import registry
registry.ensure_discovered()
selector = registry.get("video_selector")
result = selector.execute({
    "prompt": PROMPT,
    "preferred_provider": "seedance",
    "operation": "text_to_video",       # or image_to_video / reference_to_video
    "aspect_ratio": "21:9",             # 21:9 / 16:9 / 9:16 / 4:3 / 1:1 / 3:4
    "duration": "10",                   # auto / 4..15
    "resolution": "720p",               # 480p / 720p
    "output_path": "projects/<proj>/assets/video/clip_01.mp4",
})

Direct call to the provider tool (only when you must bypass the selector):

seedance = registry.get("seedance_video")
seedance.execute({
    "prompt": PROMPT,
    "model_variant": "standard",   # "standard" or "fast"
    "operation": "text_to_video",
    "aspect_ratio": "21:9",
    "duration": "10",
    "resolution": "720p",
    "generate_audio": True,
    "seed": 12345,                 # optional, for reproducible variations
    "output_path": "...",
})

Prompt structure — The Higgsfield Methodology (canonical as of 2026)

CRITICAL: Open every prompt with a shot-structure declaration. Seedance rewards prompts that declare format upfront before any creative description. This is the single biggest quality lever.

Opener templates (copy one verbatim, then extend)

For action/combat/multi-shot (highest-performing format):

Montage, multi-shot Hollywood action, don't use one camera angle or single cut, cinematic lighting, photorealistic, 35mm film quality, ARRI ALEXA aesthetic, heavy film grain, sharp but imperfect focus, motion blur on fast actions, halation on highlights, soft highlight rolloff, wide-angle lens with strong distortion, subtle chromatic aberration near frame edges, no 3D, no cartoon, no VFX aesthetic.

For single-POV continuous shots (orbs, walkthrough):

Single continuous shot, first-person POV perspective, the camera IS [his/her] eyes, hyper-chaotic handheld motion, completely unstabilized, violent raw human movement, constant micro-jitters, aggressive head swings, abrupt jerks, frequent over-rotation, no smoothness at all, no cuts, no zoom, 35mm film, photorealistic.

For locked-POV reaction scenes:

One continuous shot, POV [setting] perspective, no cuts, no zoom, natural head movement, photorealistic, 35mm film grain.

Body structure (after the opener)

1. Environment/location — sensory detail (wet asphalt, sodium lamps, neon bleed, rain particulates, volumetric haze)
2. Character block — with reference tags and identity-lock language (see Reference-to-video below)
3. Enemy/secondary character block — same detail level
4. Beat-by-beat choreography with TEMPORAL MARKERS: 0–3s: … 3–6s: … 6–10s: …
5. VFX inline in brackets: [VFX: branching white-blue electric arcs pulsing along forearms, sparks jumping between fingers]
6. Slow-motion markers: write RAMPS TO SLOW MOTION before the impact beat, SNAPS BACK TO REAL TIME on resume
7. Sound design block: either no music, only raw SFX or explicit SFX sequence. Music language stays textural.

Combat vocabulary (proven to hit)

• snaps forward, lunges, sprints, weaves, chambers, drives, pivots, redirects, ducks, slips
• explodes outward, devastating, raw force, kinetic, overload, compresses, erupts, fractures, ripples
• Avoid soft verbs: attacks, hits, fights — these read generic and Seedance underdelivers on them

Camera behavior — state what it IS and ISN'T doing

Seedance misfires when camera intent is ambiguous. Always explicitly negate what you don't want:

• no cuts (for continuous POV)
• no zoom (prevents unnatural perspective punch-ins)
• no stabilization (when you want chaotic handheld)
• no smoothness at all
• no 3D, no cartoon, no VFX aesthetic — counter-intuitive but forces photoreal skin/texture/lighting even when the scene has heavy VFX elements

Realism enforcement phrase

When the brief has VFX but you want photoreal skin/textures (not plastic Marvel-cartoon look), include:

no 3D, no cartoon, no VFX aesthetic — photorealistic textures, real skin pores, authentic fabric detail, grounded in reality

Format priority (Higgsfield empirical ordering)

Format	Best for	Pattern
Transformation	calm → threat → transformation → aftermath	6 numbered shots × 2.5s each @ 15s total
Orbs	single continuous POV	1 shot × 15s, hyper-chaotic handheld
Fights	combat choreography	Beat-by-beat, clear power mismatch, RAMPS/SNAPS
POV	locked reaction	Continuous, "no cuts no zoom" mantra
Animation	stylized 3D	@image keyframe + timed segments

The 2.5-second-per-shot rhythm appears optimal for multi-shot generations.

Legacy 8-part template (use only for single simple shots, not action)

Seedance 2.0 is unusually literal about camera language, multi-shot cuts, and quoted dialogue. Use this 8-part template:

[Shot / framing] + [Camera movement] +
[Subject description — physical detail that must persist across shots] +
[Action beat 1] → [optional cut] → [Action beat 2] +
[Setting / environment] + [Lighting / palette] +
[Style / grade / era] + [Audio — ambient, diegetic, music, dialogue]

Multi-shot inside one generation

Seedance honors explicit shot lists inside a prompt. Format each shot:

Shot 1 (wide establishing, slow aerial push-in): ...
Shot 2 (medium close-up, handheld): ...
Shot 3 (extreme close-up, rack focus): ...

Keep subject description consistent across shots for identity stability.

Lip-sync from quoted dialogue

Aang stands on the cliff edge, staff raised, wind in his cloak.
Aang says: "I won't run anymore."
Sokka, half a step behind, replies: "Then we fight."

Use Character says: "..." / Character replies: "..." exactly — mouth shapes key off quoted strings. Keep each line under ~6 words; longer lines risk drift on fast clips.

Audio cues that work

Ambient: distant thunder rolling over mountains, wind through reeds, crackling campfire Diegetic: boots crunching snow, staff planting on stone, wingbeats overhead Music direction (light touch only): low orchestral swell building, taiko drums entering on Shot 3 Do not request complex multi-instrument scores — keep music language textural.

Reference-to-video

When you have character / product / wardrobe references, use the reference-to-video endpoint. Seedance 2.0 honors an explicit bracket tagging syntax:

[reference_image: hero_portrait.png]
[identity_lock]
The same character — bald, blue arrow tattoo, orange robes — consistent across all shots, no drift or deformation. Do not alter clothing category or primary color.

Shot 1 (wide, slow push-in): hero walks across the snowy Air Temple courtyard, wind lifting robes.
Shot 2 (medium close-up): hero turns toward camera, staff in hand.
Shot 3 (extreme close-up, rack focus): hero's eyes open, wind whipping.

Identity-anchor phrases that measurably reduce face drift (stack them — redundancy helps):

• the same character
• consistent across different scenes / all shots
• maintain exact appearance from reference image
• no deformation, no drift, no face morph
• Do not alter clothing category or primary color

Single-reference workflow (common in practice): When you only have one photo:

• Use a clear, front-facing portrait with neutral lighting and minimal motion blur; avoid occluded faces (e.g., phones, sunglasses, heavy shadow).
• Reuse the SAME reference image across all shots — do not generate new refs per shot.
• Put all shots in ONE prompt under a single [identity_lock] block so the model treats them as a coherent sequence.
• If wardrobe is changing by design (e.g., civilian → costume), describe the costume verbatim on every shot it appears and add Do not alter clothing category or primary color to lock it once generated.

Anti-drift fallback: If face morphs across frames on first render, drop to a shorter duration (5-6s instead of 10s), tighten the identity-lock language, and if you have multiple reference images, cull to the 3 most consistent ones rather than flooding with 9.

Parameter guidance

Parameter	Guidance
duration	5–8 for hero shots, 10–12 for full scenes with multi-shot cuts, 4 for quick inserts. auto when unsure.
aspect_ratio	21:9 for cinematic trailers, 16:9 for broadcast / YouTube, 9:16 for Reels/Shorts/TikTok
resolution	720p default. Drop to 480p for cost-capped batch previews, not for finals
generate_audio	Keep on unless you have a specific reason to mute — Seedance's moat is synced audio. Strip audio downstream in compose if needed.
model_variant	standard for hero/cinematic shots; fast only for b-roll, previews, or when latency is the hard constraint
seed	Set a seed before iterating variants of a chosen shot — everything else held constant

What to avoid

Don't	Why
Cram four-plus simultaneous character actions into one shot	Motion coherence breaks; split into multi-shot
Request readable text / logos inside the clip	Text rendering is unreliable — handle text in Remotion overlay
Mix conflicting lighting ("bright noon" + "neon night")	Model picks one and ignores the other
Write dialogue longer than ~6 words on fast-cut shots	Lip-sync drift
Use fast variant for slow-mo, multi-shot, or complex camera moves	Routinely misses on first try — route to standard
Generate music through Seedance audio	Texture-only is fine; for real scoring use music / pixabay_music / elevenlabs and mix in compose
Bypass video_selector without a reason	Loses cost/availability/fallback handling and scoring context

Iteration strategy

1. Block out shape with a single duration=5 fast T2V pass at the intended framing. Confirm the composition works.
2. Lock the seed once the composition reads.
3. Upgrade to standard with the same seed, tighten camera and lighting language.
4. Extend and add shots — move to multi-shot or longer duration only after a single-shot version is clean.
5. Keep a per-clip README with prompt + seed + variant for every shot that makes the cut, so the compose stage can re-render consistent retakes.

Integration notes for OpenMontage pipelines

• Cinematic pipeline: Seedance 2.0 is the default video model. Use 21:9 for hero, multi-shot for montage beats, reference-to-video when the brief has a visual bible.
• Animated explainer: Use Seedance 2.0 for the establishing / mood clips only; most shots should stay in Remotion. Don't replace Remotion motion graphics with Seedance — different tool, different job.
• Screen demo / podcast / clip factory: Seedance is not the right default — these are footage-led. Only use for stylized cold-opens.
• Cost discipline: standard at 10 s ≈ $3.03 per clip. Budget accordingly in the proposal stage. fast at 5 s ≈ $1.21 for previews.

Verification checklist for every Seedance shot

• Motion reads coherently at the chosen shot length
• Audio is actually synced (check dialogue + foot/impact hits)
• Character identity matches reference / prior shots
• Camera direction matches the prompt (no auto-dolly when you asked for static)
• No readable text the model tried to render
• Grade matches the approved style playbook
• Output duration matches what you requested (some endpoints round)

Sources

• fal.ai Seedance 2.0: https://fal.ai/seedance-2.0
• fal.ai how-to-use: https://fal.ai/learn/tools/how-to-use-seedance-2-0
• Replicate bytedance collection: https://replicate.com/bytedance
• HeyGen Seedance 2.0: https://www.heygen.com/blog/introducing-seedance-2-and-heygen
• Runway Seedance: https://runwayml.com/product/seedance
• BytePlus Dreamina Seedance 2.0: https://www.byteplus.com/en/product/seedance
• Freepik Seedance 2.0: https://www.freepik.com/seedance-2
• Higgsfield Seedance 2.0: https://higgsfield.ai/seedance/2.0
• Pollo Seedance 2.0: https://pollo.ai/m/seedance/seedance-2-0
• ByteDance Seed official: https://seed.bytedance.com/en/seedance2_0
• Seedance 2.0 Wikipedia: https://en.wikipedia.org/wiki/Seedance_2.0