Runway vs Stability AI: Token Pricing, Speed & Intelligence
Full comparison of Runway and Stability AI — live token pricing, latency, throughput, context window, strengths, weaknesses, and best use cases. Rates sourced from public APIs — verify before use.
Runway
Gen-4 video generation API — cinematic quality text-to-video and image-to-video
Runway is a creative AI company best known for its Gen series of video generation models. Gen-4 and Gen-4 Turbo are available via API, producing cinematic-quality video from text or image prompts. Runway is widely used in professional film and advertising production. Pricing is per second of generated video.
Stability AI
Stable Diffusion 3.5 Large and Stable Image Ultra — open-weight image generation
Stability AI is the creator of Stable Diffusion, the most widely deployed open-weight image generation model family. The 2026 API offers Stable Diffusion 3.5 Large (highest quality), SD 3.5 Medium (balanced), and Stable Image Ultra for photorealistic output. All SD 3.5 models are open-weight and available for self-hosting. Stability AI also offers Stable Video Diffusion for short video generation.
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Live token pricing
Strengths and weaknesses
Runway
Stability AI
Key differentiators
Gen-4 is Runway's cinematic-quality video generation model, trusted by professional film and advertising studios — with Gen-4 Turbo offering a faster, lower-cost alternative via the same API.
Stable Diffusion 3.5 models are open-weight and self-hostable — enabling the largest fine-tuning and LoRA ecosystem of any image generation model family, with full control over the generation pipeline.
Frequently asked questions
Runway FAQs
How is Runway priced?
Runway charges per second of generated video. Gen-4 is $0.100/second and Gen-4 Turbo is $0.050/second. See runwayml.com/pricing for current rates.
What is Gen-4?
Gen-4 is Runway's latest video generation model, producing cinematic-quality output from text or image prompts. It is used in professional film, advertising, and visual effects production.
What is the difference between Gen-4 and Gen-4 Turbo?
Gen-4 produces higher-quality output at $0.100/second. Gen-4 Turbo is faster and cheaper at $0.050/second, with slightly lower quality. Both support text-to-video and image-to-video generation.
Stability AI FAQs
What is Stable Diffusion 3.5?
Stable Diffusion 3.5 is Stability AI's latest generation of open-weight text-to-image models. SD 3.5 Large offers the highest quality; SD 3.5 Medium is a balanced option for production use. Both are available for self-hosting.
How does Stability AI compare to FLUX?
FLUX 1.1 Pro generally outperforms SD 3.5 on photorealism and prompt adherence benchmarks. However, SD 3.5 has a much larger community ecosystem of fine-tuned variants and LoRAs, making it more flexible for specialised use cases.
Can I self-host Stable Diffusion 3.5?
Yes. SD 3.5 Large and Medium weights are publicly available under the Stability AI Community License. You can run them on any GPU with sufficient VRAM — SD 3.5 Medium requires ~8GB VRAM; SD 3.5 Large requires ~24GB.
Provider resources
Runway — Gen-4 video generation API — cinematic quality text-to-video and image-to-video
Runway is a creative AI company best known for its Gen series of video generation models. Gen-4 and Gen-4 Turbo are available via API, producing cinematic-quality video from text or image prompts. Runway is widely used in professional film and advertising production. Pricing is per second of generated video.
Gen-4 is Runway's cinematic-quality video generation model, trusted by professional film and advertising studios — with Gen-4 Turbo offering a faster, lower-cost alternative via the same API.
Stability AI — Stable Diffusion 3.5 Large and Stable Image Ultra — open-weight image generation
Stability AI is the creator of Stable Diffusion, the most widely deployed open-weight image generation model family. The 2026 API offers Stable Diffusion 3.5 Large (highest quality), SD 3.5 Medium (balanced), and Stable Image Ultra for photorealistic output. All SD 3.5 models are open-weight and available for self-hosting. Stability AI also offers Stable Video Diffusion for short video generation.
Stable Diffusion 3.5 models are open-weight and self-hostable — enabling the largest fine-tuning and LoRA ecosystem of any image generation model family, with full control over the generation pipeline.
Key strengths compared
Runway
- Gen-4 produces cinematic-quality video used in professional film and advertising
- Gen-4 Turbo at $0.050/second offers faster generation at lower cost
- Strong motion quality and temporal consistency
- Video generation only — no text, image, or audio LLM models
- Gen-4 at $0.100/second is among the higher-priced video generation APIs
Stability AI
- Open-weight SD 3.5 models — self-host on any GPU cloud
- Largest community ecosystem of fine-tuned variants and LoRAs
- Stable Image Ultra for photorealistic output
- Image quality trails FLUX 1.1 Pro and Midjourney on photorealism benchmarks
- Company has faced financial challenges and leadership changes
Key weaknesses compared
Runway
- Video generation only — no text, image, or audio LLM models
- Gen-4 at $0.100/second is among the higher-priced video generation APIs
- Generation latency is higher than text inference
Stability AI
- Image quality trails FLUX 1.1 Pro and Midjourney on photorealism benchmarks
- Company has faced financial challenges and leadership changes
- SD 3.5 adoption slower than FLUX in the community
Provider category context
Runway is a frontier lab, founded in 2018. Stability AI is a frontier lab, founded in 2020. Both are frontier lab providers — the comparison is primarily about pricing, model selection, and feature differentiation within the same tier.
How to choose between them
Both Runway and Stability AI are frontier labs with proprietary models. Choose based on benchmark performance for your specific task: Runway leads on gen-4 produces cinematic-quality video used in professional film and advertising, while Stability AI leads on open-weight sd 3.5 models — self-host on any gpu cloud. For cost-sensitive workloads, compare the cheapest model tier from each provider in the pricing table above — the gap between efficient-tier models is often larger than between flagship models.