Best AI Video Prompt Tools in 2026 (Veo, Kling, Runway)

TL;DR: The best AI video prompt tool in 2026 depends on how much of the shot you need to specify. Seedance 2.5 and Kling 3.0 publish real prompt grammars. Veo 3.1 has always-on audio. Runway Gen-4.5 is silent. Sora leaves the API on September 24, 2026.

Start with what breaks this month. OpenAI's deprecations page records that developers were notified on March 24, 2026 of the Videos API and the Sora 2 family being deprecated, with "removal from the API on September 24, 2026". Six entries, and the recommended-replacement column is blank for all of them. If your pipeline calls sora-2, it stops working in under a month and OpenAI is not saying where to go. So: which AI video prompt tool should you write for now?

What Should You Use Instead of Sora 2?

It depends what you used Sora for, because no single model inherits all of it. The table below maps each use to what the replacement documents.

Our Sora 2 migration guide goes deeper. Short version: pick on the capability you were leaning on, not the brand.

What Counts as an AI Video Prompt Tool in 2026?

A model you can write a prompt into, plus the parameters sitting beside the prompt.

The other, smaller category is prompt managers and enhancers, ourselves included, covered in our prompt manager roundup. This page covers the eleven models that render the clip, because that is where the constraints live. No prompt manager can give Runway a last frame its schema does not accept.

How Did We Rank These Without Comparing Output Quality?

By ranking on documentation, because picture quality is the thing we did not measure.

The honest disclosure, up front. We did not generate video for this post, and we did not run one prompt through eleven models and compare results. Neither did most pages competing for this keyword, whatever their screenshots imply. Comparisons at that scale age within weeks of a version bump.

What is checkable is what each vendor commits to in writing: clip length, resolutions, whether sound comes out, whether you can pin the first and last frames, whether a syntax exists that the model parses. Those facts have URLs and dates. So the axis is how much of the shot the vendor lets you specify and documents. Where a vendor documents nothing, this page says "not documented" and does not guess from a competitor.

What Can You Actually Control in the Shot?

Duration, resolution, frame conditioning and extension, and the answers differ more than the marketing suggests. Every cell below is from the vendor's own documentation, accessed August 29, 2026.

Sources, all accessed August 29, 2026: Seedance and its 2.5 tutorial · Kling text-to-video and image-to-video · Veo · LTX-2.5 · Vidu text-to-video and extension · Grok Imagine · Wan 2.7 text-to-video and image-to-video · Luma · Runway OpenAPI · Pika 2.5 · OpenAI deprecations.

Two cells deserve a second look. Veo 3.1's eight seconds reads badly next to Seedance's thirty until the extension clause: Google documents that you can "extend videos that you previously generated with Veo by 7 seconds and up to 20 times", stitched to at most 148 seconds. Kling's fifteen is a hard ceiling, because its API index lists video extension for the 1.0, 1.5 and 1.6 generations only. The full set of couplings is in our video duration reference.

Which Models Make Sound, and Which Publish a Prompt Syntax?

This is where the field separates, and it is what most roundups skip.

Three findings deserve stating plainly.

Kling is the only audio-capable model here that ships silent. Its settings.audio field defaults to off, and the spec spells out the consequence: "The generated video has no audio." Everyone else who makes sound makes it unless you opt out. If your Kling clips are mute, that is why.

Runway Gen-4.5 has no audio capability at all. Its text-to-video and image-to-video schemas expose promptText, ratio, duration, seed, outputFormat and moderation settings, and nothing else. Runway ships audio elsewhere, but not on this model.

Only Luma documents a loop. Ray 3.2 exposes video.loop, which "generates a seamlessly looping video" and is rejected alongside a ten-second duration, HDR, an end frame or keyframes. Runway has a loop parameter, but it lives on the sound-effect endpoint: "Whether the output sound effect should be designed to loop seamlessly." That is audio, not video. No other vendor here documents a video loop flag.

Which AI Video Prompt Tools Rank Highest on Documented Control?

Ordered by how much of the shot each vendor lets you specify in writing.

1. Dreamina Seedance 2.5. The most documented prompt surface here. ByteDance publishes an ordering formula, "subject + action/event + scene and environment + visual style + camera movement/shot cuts + sound", plus an asset-reference convention and four sound markers. It runs to thirty seconds, takes first and last frames, edits and extends existing video, and its docs say it can "accept up to 50 omni reference assets per request".

2. Kling 3.0 and 3.0 Omni. The only formal shot grammar in the field, published in the API reference rather than the guides. Prompts cap at 3,072 characters, duration is every integer from 3 to 15, and 4k is available at maximum length. The cost is no extension on 3.x and no published output frame rate.

3. Veo 3.1 on the Gemini API. Weakest on duration, strongest on sound. Audio is always on, lastFrame interpolates between two images, three reference images steer style and content, extension reaches 148 seconds. Still Preview, and 1080p or 4k forces eight seconds.

4. LTX-2.5. The best-documented API here and the only one letting you choose a frame rate, from 24, 25, 48 or 50. It ships an automatic duration mode where "the model picks the length itself, from your prompt". The catch: twenty seconds exists only on the Fast variant at 720p or 1080p at 24 or 25 fps, and retake, extend and reframe are gone from both 2.5 variants.

5. Vidu Q3. Sixteen seconds, audio on by default including dialogue and sound effects, a start-and-end-frame endpoint and a separate lip-sync operation. It is not higher because Vidu publishes no prompt-writing guide, and extension is documented for Q2 only, so sixteen seconds is a hard budget.

6. Grok Imagine Video 1.5. One to fifteen seconds, three resolutions, reference images, extension of two to ten seconds, audio on by default. Its distinctive feature is voice: attach up to three preset voices and address them in the prompt by index token. That is the closest thing to a grammar xAI publishes.

7. Wan 2.7 on Alibaba Cloud Model Studio. Under-discussed and capable. Two to fifteen seconds, a real negative_prompt capped at 500 characters, first-frame, first-and-last-frame and video continuation, and automatic dubbing where "the model generates background music or sound effects that match the video content". Supply an audio file instead and it drives the voice.

8. Luma Ray 3.2. Five or ten seconds only, the shortest range here, but the most granular frame control: start and end frames plus one to sixty-four keyframes pinned to explicit output-frame indices. It is also the only loop in the field, with HDR and EXR export. Nothing about audio appears in its video generation guide.

9. Runway Gen-4.5. Two to ten seconds, a seed, professional output formats including ProRes and true HDR, and a large third-party catalogue alongside its own. But on Gen-4.5 the image input schema says "Only a first frame is supported.", with no negative prompt and no audio.

10. Pika 2.5. Five seconds for text-to-video, a real negative prompt, and Pikaframes for two to five keyframes. Pika publishes no prompt-writing guide, and its named effects take a fixed enum rather than a prompt.

Not ranked: Sora 2. Removed from the API on September 24, 2026, with no named successor. Do not start a pipeline here.

How Do You Write the Same Shot for Different Models?

You rewrite the parts each vendor documents and leave the rest as plain description. The same shot, five ways, every syntax element from that vendor's own docs.

Veo 3.1 reads speech from quotation marks in the prose, per Google's own instruction: "Use quotes for specific speech."

A lighthouse keeper climbs a narrow spiral stair at dawn, one hand on the
cold rail. Slow dolly follow, low angle, shallow focus, cold blue tones.
He pauses at the top and says: "The light held. That is all that matters."
Wind pressing against glass, boots on iron, a distant foghorn.

Kling 3.0 reads a semicolon-separated grammar of shot number, shot seconds and shot words, the seconds summing to the total:

shot 1, 4, low angle on a lighthouse keeper starting up a narrow spiral
stair at dawn, cold blue tones, slow dolly follow;
shot 2, 3, close on his hand tightening on the cold iron rail;
shot 3, 5, wide from the lamp room as he reaches the top and looks out
over the water, foghorn in the distance;

Seedance 2.5 puts the subject first and marks sound with brackets: () music, <> effects, {} dialogue, 【】 subtitles.

0-4s: A lighthouse keeper climbs a narrow spiral stair at dawn. Low angle,
slow dolly follow, cold blue tones. <boots on iron, wind against glass>
4-8s: He reaches the lamp room and looks out over the water.
{The light held. That is all that matters.} <distant foghorn>
(sparse low strings, held)

Runway Gen-4.5 takes plain prose under 1,000 characters, with no sound and no last frame, so it all lives in the description:

Low angle, slow dolly follow. A lighthouse keeper climbs a narrow spiral
stair at dawn, one hand on the cold iron rail, cold blue tones, shallow
focus. He reaches the top and looks out over grey water. Handheld weight,
35mm, natural window light falling from above.

LTX-2.5 takes one flowing paragraph, can pick its own length, and generates sound unless generate_audio is false:

A lighthouse keeper climbs a narrow spiral stair at dawn, one hand on the
cold iron rail, then reaches the lamp room and looks out over grey water
as a foghorn sounds in the distance. Low angle, slow dolly follow,
shallow focus, cold blue tones, natural light falling from above.

The imagery is identical in all five; what moves is the scaffolding. Shot numbers for Kling, timestamps and brackets for Seedance, quotation marks for Veo, nothing at all for Runway. That is the practical meaning of "documented prompt grammar". For the sound layer in depth, our AI video sound design guide works through the audio cues per model.

Where Does Prompt Architects Fit in This List?

Nowhere in it, deliberately. We are not a video model and should not be ranked as one.

Prompt Architects generates the prompt. The model renders it. We have no pixels and no render queue. We turn a rough idea into a structured video prompt shaped for the model you are about to call, then keep it, so the next shot starts from the one that worked. Our free Veo 3 prompt generator shows the shape of it.

One thing to be straight about: video prompt generation sits on the Advanced and Team plans, not Pro. The comparison table on our pricing page marks it unavailable on Free and Pro as of August 2026. Image prompt generation is on Pro; video is not.

If your problem is which model should render this, nothing here needs us. If it is that you rewrite the same twelve-line camera-and-lighting preamble every time and then lose it, that is the part we solve.

Which One Should You Actually Pick?

Match the model to whichever constraint bites first.

1. You need dialogue on the beat. Veo 3.1. Audio is always on, with published cue conventions for speech, effects and ambience.
2. You need one long uninterrupted take. Seedance 2.5, at up to thirty seconds.
3. You need several shots from one prompt. Kling 3.0, the only published shot grammar.
4. You need to control frame rate. LTX-2.5, the only one offering 48 and 50 alongside 24 and 25.
5. You need a clip that loops cleanly. Luma Ray 3.2, the only documented video.loop in the field.
6. You need ProRes or true HDR delivery. Runway Gen-4.5, if you can live without sound.
7. You need a real negative-prompt parameter. Wan 2.7 or Pika 2.5. Most 2026 flagships dropped it.
8. You are still calling sora-2. Move now. Removal is September 24, 2026, with no named replacement.

One note on what this page omits. No prices: video billing is metered per second or per credit and changes faster than a blog post can track, so read each vendor's pricing page. No star ratings. No quality verdict, because we did not measure one. What is here is what eleven vendors wrote down, with the URL and date beside it, so you can check every line yourself. For a head-to-head on the three most-searched names, our Veo, Sora and Kling comparison goes deeper.