Seedance 2.5 First To Last Frame Specifications
Last verified: September 9, 2026
Most video generators animate one starting image or leave the destination open. This tool requires both an opening and closing frame, which means the generated motion is planned around a defined start and finish. On the Seedance 2.5 First To Last Frame page, the prompt explains what should happen between those endpoints while aspect ratio and duration define delivery geometry and pacing.
The underlying model builds on ByteDance's unified multimodal audio-video joint-generation architecture, with an emphasis on foundational and reference-based generation. In practical terms, the model solves a constrained temporal path rather than inventing every visual state from text alone: the creator supplies two visual anchors and directs the middle in language.
Official BytePlus documentation lists first-and-last-frame image-to-video as a supported Seedance 2.5 capability, while the model page emphasizes longer narratives and precise reference control. That changes the creator's job from hoping for a usable ending to specifying the intended final composition before spending credits on the render.
Explore more first to last frame
Verified Endpoint Workflow Limits
Platform-listed inputs, settings, output details, and generation estimates.
Required inputs
Prompt, First Frame, and Last Frame
Duration range
4–30 seconds in 1-second increments
Aspect ratios
1:1, 3:4, 4:3, 9:16, 16:9, or auto
Resolution choices
480p, 720p, or 1080p
Prompt capacity
Up to 30,000 characters
Endpoint Workflow Decision Matrix
Choose the workflow according to endpoint certainty, available assets, iteration budget, and required output count.
| Criterion | Our Tool | Alternatives | Best For |
|---|---|---|---|
| Endpoint certainty | Both endpoint frames are required, so the shot is directed toward a specified ending. | Use Image To Video when only the opening frame is available and the ending may remain open. | Match transitions, visual transformations, and before-and-after reveals |
| Available source assets | Best when opening and closing compositions have already been designed. | Use Text To Video when no endpoint images have been prepared. | Storyboarded sequences with approved key images |
| Iteration budget | The premium render has an expected cost of 161 credits and an estimated wait of 150 seconds. | A lower-cost or faster workflow is preferable when testing many undeveloped concepts. | Finalized ideas where endpoint control outweighs rapid iteration |
| Variant count | One generation returns one video. | A workflow designed for several outputs is better when selection breadth matters more than one directed result. | A single approved transition or deliverable |
Organize the Shot Request in One Form
Budget the Render Before Submission
Apply Web Search Only When Needed
Four-Step Endpoint Render Protocol
Prepare, configure, generate, and download one video in four steps.
Step 1: Write the motion brief
Describe the subject's action, intended visual change, camera path, pacing, and final state in the Prompt field.
Step 2: Upload both endpoint frames
Add the required First Frame and Last Frame, checking that subjects and scene elements meant to stay consistent are clearly represented in both.
Step 3: Set framing and duration
Choose an aspect ratio and select a duration from 4 to 30 seconds based on how much motion or transformation must occur.
Step 4: Generate and download
Click Generate, allow for the expected render time of about 150 seconds, then download the completed premium video.
Endpoint Preflight Verification
Verify these four conditions before spending credits on a slow generation.
Before you generate, verify subject continuity between frames
Cause: Large changes in identity, scale, pose, wardrobe, props, or viewpoint can force the model to resolve several visual conflicts at once.
Fix: Align the elements that must remain stable and leave only the intended action or state change for the video to solve.
Retry: Retry after replacing one or both endpoint frames with a more compatible pair.
Before you generate, verify that the prompt explains the middle
Cause: A prompt that only repeats the opening and ending states does not provide a clear motion path, camera direction, or pacing.
Fix: State what moves, how it moves, what the camera does, and which details must remain unchanged.
Retry: Retry after rewriting the prompt around one explicit action sequence.
Before you generate, verify the selected aspect ratio
Cause: A canvas that conflicts with the endpoint compositions may crop or reframe important subjects.
Fix: Select the ratio that matches the intended delivery format and protects the important content in both endpoints; use auto when a system-selected option is preferable.
Retry: Retry after changing the ratio or preparing endpoints composed for the selected canvas.
Before you generate, verify that duration matches the visual change
Cause: A major transition compressed into a short clip can look rushed, while a minimal change stretched across a long clip can lose direction.
Fix: Give complex movement more time and use a shorter duration for subtle camera motion or a small state change.
Retry: Retry after changing duration only, so its effect on pacing can be evaluated clearly.
Frequently Asked Questions
Are both endpoint frames required on this page?
Yes. The required inputs are a Prompt, First Frame, and Last Frame. If only an opening image exists, use Image To Video instead; if no prepared images exist, use Text To Video.
What belongs in the prompt when the frames already define the endpoints?
Describe the motion between the two compositions: subject action, camera movement, pacing, intended transformation, and details that must remain stable. Avoid spending most of the prompt restating information already visible in both frames.
How should I choose a duration between 4 and 30 seconds?
Match duration to the amount of visual change. A subtle push-in or lighting shift generally needs less time than a location change, assembly sequence, or multi-stage transformation. Use enough time for each action to remain readable.
Can the generated video include an audio track?
Yes, the platform facts list audio-track support for the output. This page does not list a separate audio-prompt input, so the documented workflow remains a text prompt plus the two endpoint frames.
Does selecting 1080p guarantee a sharper result?
No resolution setting can guarantee perceived sharpness. The platform offers 1080p, but visible detail also depends on the clarity and compatibility of the endpoint frames, the complexity of the motion, lighting, and how much the scene changes.
What should I expect from the Web Search toggle?
Web Search is listed as an optional input. Its detailed retrieval behavior is not specified for this workflow, so write a self-contained visual prompt and treat the toggle as supplementary rather than required.
Are seed, negative-prompt, or fixed-camera controls available?
Those controls are not listed for this tool page. Do not plan a generation around them; express the desired camera behavior and visual constraints directly in the main prompt instead.
Can I use the generated video commercially?
Commercial-use rights depend on the applicable service terms and the rights attached to the uploaded endpoint frames. Review those terms before paid distribution, and only upload images you are authorized to use.