The number that decides what AI video actually costs you is not the monthly subscription. It is credit burn per second of output. Runway’s flagship model consumes roughly 25 credits for every second it generates, which means the 625-credit plan renders about 25 seconds of finished video a month. That is the kind of arithmetic no pricing page puts on the front.
This guide compares seven tools across three product types, and leads with credit burn, clip length and commercial terms rather than quality impressions. Figures come from vendor pricing pages and current pricing analysis. Where sources disagree or a vendor does not publish a figure, that is stated rather than smoothed over.
Three different products
These tools are routinely listed together and do three unrelated jobs.
Generative clip models create footage from a text prompt or still image. Runway, Kling, Google Veo and Pika belong here. They produce short clips, they meter by credit or by second, and none of them makes a finished video on its own.
Avatar and presenter tools put a synthetic person on screen reading a script. Synthesia and HeyGen belong here. They are not cinematic generators and should not be shortlisted against Runway or Veo for b-roll.
Template-based editors assemble a complete video from a prompt using stock footage, voiceover and captions. InVideo belongs here. The output is a finished video rather than a generated shot.
Choosing across categories is the most common mistake. If you need a presenter explaining a product, a clip model is the wrong purchase however good its output looks.
How credits actually work
Every generative tool here meters by credit, and the burn rate varies enormously by model.
Runway publishes the clearest breakdown: Gen-4.5 consumes about 25 credits per second, Gen-4 about 12, and Gen-4 Turbo about 5. A ten-second Gen-4.5 clip is therefore roughly 250 credits. On the 625-credit Standard plan, that is two and a half clips a month before you run out.
Kling is materially cheaper per second, with a five-second standard generation reported at around 20 credits and per-second costs commonly cited near $0.07 to $0.10.
Veo 3.1 is sold per second through its API tiers: roughly $0.05 per second on Lite without audio, around $0.15 on Fast, and $0.40 to $0.75 on Standard with native audio and 4K.
Pika charges around 12 credits for a five-second 480p clip, which means its 80-credit free allowance covers roughly six attempts a month.
Two practical rules follow. First, iteration is the real cost, because you will rarely accept the first generation, and every retry burns the same credits. Second, cheaper models exist inside expensive platforms: drafting on a Turbo-class model and reserving the flagship for the final render can cut consumption by a factor of five.
Clip length is a hard limit
Length is not a matter of paying more. Each model has a ceiling, and reported maxima differ sharply: Kling extends furthest at around two to three minutes, Veo 3.1 reaches roughly 60 seconds, and Runway caps near 40 seconds.
For anything longer, the workflow is to generate several short clips and assemble them in an editor, which means character and scene consistency across shots becomes the constraint rather than duration itself. If your project needs one continuous shot beyond 40 seconds, that requirement alone narrows the field.
Generative clip models
1. Runway
Runway is the production suite rather than just a model, offering directorial controls such as motion brush and camera moves that the pure text-to-video tools do not match. It has also begun surfacing third-party models including Veo and Kling inside its own dashboard, which suggests the interface is becoming the product.
The free tier needs care: 125 credits granted once, which never renew, with watermarked 720p output and a project cap. At Gen-4.5 rates that is about five seconds of flagship video, one time. Paid tiers are reported at roughly $12 to $15 for Standard with 625 credits, $28 to $35 for Pro with 2,250, and $76 to $95 for Max with 9,500, with annual billing saving around 20%. API credits are billed at roughly $0.05 each.
Suits: filmmakers and agencies who need to direct a shot rather than accept what a prompt returns, and who will budget for iteration.
2. Kling
Kling is the value option and currently the length leader. Its 3.0 release added multi-shot sequences with subject consistency across camera angles, which addresses the main weakness of assembling longer videos from short generations.
The free account provides roughly 66 daily credits, but output is watermarked and, importantly, does not carry unrestricted commercial rights. Paid tiers are reported around $6.99 for 660 credits and $25.99 for 3,000, which is the lowest entry point among the clip models here.
Suits: high-volume social production and anyone needing clips beyond a minute.
3. Google Veo
Veo 3.1 is the quality benchmark most current comparisons reach for, with native 4K and synchronised audio generated alongside the video rather than added afterwards. That audio capability is the genuine differentiator: most models here produce silent footage.
Access runs through Google AI plans and the API rather than a standalone subscription, and per-second pricing spans a wide range depending on tier and whether audio is included. One consistent caveat across sources: availability remains restricted in parts of Europe, so confirm access in your region before planning around it.
Suits: brand and cinematic work where audio and resolution matter more than granular directorial control.
4. Pika
Pika is built for fast, playful short-form work, with named effects for transformations, object insertion and swaps rather than cinematic control. It is consistently placed as the budget option in current rankings.
Its free tier is precise and restrictive: 80 monthly credits, 480p only, watermarked, no commercial use, and you cannot buy add-on credits without upgrading. Paid tier labels and prices are reported inconsistently across current sources, with the same figures attached to different plan names, so check Pika’s own pricing page rather than trusting a quoted tier. Annual billing is roughly 20% cheaper than monthly.
Suits: social creators making effect-driven clips who can work at low resolution while testing.
Avatar and presenter tools
5. Synthesia
Synthesia generates a presenter reading your script, in many languages, without filming anything. It is used for training, onboarding and internal communications, where the alternative is booking a studio.
Pricing is reported from roughly $14 to $29 per month depending on billing and tier, with the entry plan commonly described as including around 10 minutes of video per month. That minute allowance, rather than the price, is what decides whether it fits.
Suits: corporate training and localised business video at scale.
6. HeyGen
HeyGen occupies the same category with a stronger emphasis on voice translation and lip-sync, which makes it the common choice for taking one recording into several languages.
Entry pricing is reported from around $29 per month, and its avatar features are metered in credits per minute of output. If multilingual presenter video is the job, our guide to AI voice generators covers the audio side in more depth.
Suits: multilingual marketing and localisation.
Template-based editors
7. InVideo
InVideo produces a complete video from a prompt: script, stock footage, voiceover, captions and transitions assembled automatically. It is the only tool here that outputs something publishable without further editing.
Its free plan allows around 10 minutes of AI-generated video per month at 720p with a watermark, and current reporting notes a weekly export quota that resets each Monday and does not roll over. Paid tiers are reported from roughly $25 monthly, or about $20 annually, rising through higher tiers, with one plan bundling access to third-party generative models.
The structural warning worth heeding: InVideo splits AI minutes, stock footage downloads, voiceover minutes and voice-clone slots into separate credit pools. Exhausting one does not free capacity in another, and that catches most heavy users within the first fortnight.
Suits: marketers and educators who need a finished video quickly rather than a generated shot.
Comparison
Based on vendor documentation and current pricing analysis. Entries marked with a dash are details we could not confirm, and we would rather leave those cells empty than guess.
| Tool | Type | Free tier | Credit burn | Max clip | Commercial use on free |
|---|---|---|---|---|---|
| Runway | Clip model | 125 one-time credits, watermarked 720p | ~25 credits/sec on Gen-4.5 | ~40 sec | Watermarked output |
| Kling | Clip model | ~66 daily credits, watermarked | ~20 credits per 5-sec clip | ~2–3 min | No unrestricted rights |
| Google Veo | Clip model | Limited via Google AI plans | ~$0.05–0.75 per second | ~60 sec | — |
| Pika | Clip model | 80 credits/mo, 480p, watermarked | ~12 credits per 5-sec clip | — | No commercial use |
| Synthesia | Avatar | Evaluation tier | Metered by video minutes | Not applicable | — |
| HeyGen | Avatar | Free entry tier | Credits per minute | Not applicable | — |
| InVideo | Template editor | ~10 min/mo, 720p, watermarked | Separate credit pools | Not applicable | Watermarked output |
There is no quality column. No vendor publishes a reproducible benchmark, model versions change every few months, and results depend heavily on the kind of footage you ask for.
Commercial use and licensing
This is where buyers most often get caught, because the terms differ tool to tool and free tiers are where restrictions concentrate.
Some platforms grant you ownership of what you generate. Others grant a usage right they retain the ability to limit. That distinction rarely appears on a pricing page and matters enormously for client work.
Two specifics worth knowing before you publish anything commercially. Kling’s free tier does not carry unrestricted commercial rights, and Pika’s free tier excludes commercial use entirely. A watermark-free export is not the same as a commercial licence, and neither is the absence of an obvious restriction.
Before using AI video in paid work, read the terms for the specific plan you hold rather than the platform generally, and check whether ownership or a revocable licence is what you are being granted.
A market that consolidated
One change worth flagging if you are working from older advice: OpenAI’s Sora was discontinued, with its closure reported at the end of March 2026, and the earlier Veo 3 API was shut down. Coverage from 2025 that ranked Sora at the top of this category is describing a product that is no longer available.
The field has consolidated around Veo 3.1, Kling 3.0 and Runway Gen-4.5, with several platforms now reselling one another’s models. Treat any specific model version named in a guide, including this one, as a snapshot.
How to choose
The right tool depends less on which is objectively best and more on what you are making. Before choosing a platform, weigh:
- Whether you need generated footage, a presenter, or a finished video
- Your realistic monthly output in seconds, not in videos
- Maximum clip length your project requires
- Whether you need synchronised audio generated with the video
- Export resolution and watermark terms on the tier you can afford
- Commercial licensing for the specific plan, not the platform
- How much iteration you expect before accepting a shot
Trying the free version first is the quickest way to find out whether a tool fits your workflow, since generation quality varies noticeably between platforms depending on the type of footage you ask for. For visuals to accompany video, see our guide to AI image generators, and for captions, AI subtitle generators.
Related guides
- Best AI Image Generators in 2026
- Best AI Subtitle Generators in 2026
- Best AI Voice Generators in 2026
- Best AI Music Generators in 2026
- Best AI Presentation Makers in 2026
Frequently asked questions
Which AI video generator is actually free?
All of them offer something, but with tight limits. Pika gives 80 monthly credits at 480p with a watermark and no commercial use. Runway grants 125 credits once, which never renew. Kling provides daily credits without unrestricted commercial rights. InVideo allows around 10 minutes a month, watermarked.
How long can AI-generated clips be?
Reported maxima differ substantially: Kling reaches roughly two to three minutes, Veo 3.1 around 60 seconds, and Runway near 40 seconds. Longer videos are assembled from multiple generations, which makes consistency across shots the real constraint.
Why do my credits disappear so quickly?
Because flagship models burn credits per second of output and every retry costs the same as the first attempt. Runway’s Gen-4.5 consumes about 25 credits per second, so a 625-credit plan covers roughly 25 seconds of finished video a month.
Can I use AI video commercially?
On paid plans usually, but free tiers frequently exclude it. Kling’s free tier does not carry unrestricted commercial rights and Pika’s excludes commercial use. Read the terms for the plan you actually hold.
Do these tools generate audio?
Most produce silent footage. Veo 3.1 generates synchronised native audio alongside the video, which is its main differentiator. Avatar tools generate speech by design, and template editors add voiceover from a script.
What happened to Sora?
It was discontinued, with closure reported at the end of March 2026, and the earlier Veo 3 API was also shut down. Guides still ranking Sora are out of date.
Conclusion
Decide which of the three products you need before comparing anything. Generative clip models produce shots, avatar tools produce presenters, and template editors produce finished videos, and no amount of quality comparison bridges those categories.
Within the clip models, the deciding numbers are credit burn per second, maximum clip length and what the free tier permits commercially. Runway offers the most control at the highest burn rate, Kling the longest clips at the lowest cost, Veo the only native audio, and Pika the cheapest experimentation at the lowest resolution. Work out your monthly output in seconds rather than in videos, and the choice usually makes itself.
