Image-to-video vs text-to-video: choosing the right starting point

Quick answer: decide what is already fixed

Start with image-to-video when the subject, composition, or visual treatment has already been approved. Start with text-to-video when you are still exploring what the scene should contain. If several specific visual moments must connect, investigate keyframe controls rather than asking one starting image to describe the whole sequence.

This is a decision about where to put creative constraints. An image can communicate an existing design, but it does not establish that the generated motion will preserve every detail.

Choose by the brief, not the label

Use the right leaderboard for the starting point

For a text-led silent shot, put FLUX 3 on the first-test shortlist: in our October 21, 2026 snapshot of Artificial Analysis’s silent text-to-video board, it scored 1094, versus 913 for Runway Gen-4.5 (720p). Runway’s result covers only 61% of the benchmark prompts because of its API prompt-length limit. This does not establish which model better animates an approved image. FLUX 3 documents keyframe controls; Runway Gen-4.5 provides a documented 720p image-led workflow. Choose the latter when that workflow and output size fit the job, and compare representative clips before switching.

The video evaluation snapshot keeps the silent and audio-enabled pools separate, with sample sizes and uncertainty.

Image-to-video: approve the still before adding motion

Runway’s image-to-video guide describes the input image as the first frame, carrying the subject, composition, lighting, and style. Its prompt guidance emphasizes motion rather than repeating everything visible. It also warns that defects in an input image can become more pronounced in motion.

For an illustrated character, our suggested first pass is to inspect the face, hands, costume, and silhouette in the still. Then ask for one meaningful action. An illustrative prompt might be: “The character turns toward the window while the camera stays still.”

Review the entire clip, especially the turn and final pose. A correct opening frame is only one acceptance criterion. See the Runway capability record for the documented model and access-route boundaries.

Text-to-video: leave room where the design is undecided

Text-to-video is a useful starting point for an exploratory landscape, a mood shot, or an abstract scene without an approved reference. Runway’s text-to-video guide separates visual information from motion information and recommends beginning with the important details rather than maximizing prompt length.

For example: “A wide shot of an empty greenhouse at dawn. Condensation catches the light as the camera moves slowly toward the open door.” This illustrates a compact brief. Decide which elements are mandatory before generating. If the exact greenhouse layout is essential, prepare or obtain a suitable reference rather than treating an evocative description as a construction drawing.

A reference image, an endpoint, and a keyframe are different controls

Read what an image input does in the selected workflow. It might establish the opening frame, supply a reference, or mark a position inside the clip. Those roles should not be assumed interchangeable.

Luma’s Ray 3.2 generation guide distinguishes start/end frames from multi-keyframe inputs placed at specified output positions. The multi-keyframe and legacy endpoint controls have different compatibility rules. Its HDR and duration descriptions contain a conflict, so we do not recommend relying on a particular combined setting without clarification. Check the Luma capability notes alongside the current parameter reference.

Pika 2.5 documents two to five ordered frames; a five-keyframe sequence is limited to 720p. More anchors therefore change both the creative setup and the eligible output. Inspect the intervening motion, not just whether the endpoints resemble the supplied images.

Separate the motion decision from the delivery specification

Before paying for iterations, write down the required aspect ratio, duration, resolution, frame rate, audio, and file format. Runway’s Gen-4.5 web specifications list 720p output and different aspect-ratio choices for text and image modes. A workflow name alone does not establish identical settings.

Pika’s model page explicitly says Pika 2.5 renders are silent. Plan an audio step if the deliverable needs sound; another audio product in the same application does not make this model’s output audible. See Pika’s capability record for the remaining documented limits.

Use a small, recorded evaluation

1. Pick one representative shot and list its non-negotiable details.
2. Prepare a clean, rights-cleared image if evaluating image-to-video.
3. Keep the motion goal and delivery settings comparable across attempts.
4. Record the exact model, mode, settings, input, prompt, date, and spend.
5. Judge the full downloaded clip against the brief, including transitions and any required sound.
6. Count rejected takes and manual corrections, not only your favorite result.

If the image itself needs repeated repair, compare that preparation effort with the text-led alternative. A useful workflow has to fit the entire job.

Check availability before committing a workflow

As checked October 21, 2026, Google’s video documentation schedules Gemini API Veo 3.1 Preview endpoints to shut down on October 22, 2026; that notice does not retire every Veo access route. OpenAI’s deprecation record lists the Sora 2 models and Videos API as shut down September 24, 2026. We do not recommend building a new workflow on those endpoints.

Its review date records when the sources were checked. Recheck the selected endpoint before adopting it.