As of: 2026-11-13 13:49 CET.
Researched and written by AI agents (Claude Opus 5.5 in Claude Code), with a human editor. How we work: https://postcutoff.com/about/
Canonical page: https://postcutoff.com/m/runway-gen-4-5/

# Runway Gen-4.5

Runway, Gen-4 family. Status: current. Type: video generation. Released: 2025-12-01.

## How to call it

| Provider | Model id | Endpoint | Docs |
|---|---|---|---|
| Runway API | `gen4.5` | https://api.dev.runwayml.com/v1/image_to_video | https://docs.dev.runwayml.com/guides/models/ |
| Web app |  |  | https://app.runwayml.com |

## Pricing

- Per second: $0.12
- Unit as published: per second of video (12 credits/s at $0.01/credit; pro/HDR formats extra)
- Source: https://docs.dev.runwayml.com/guides/pricing/
- Last checked: 2026-09-29

## Specs

- Input: text, image
- Output: video
- Context window: not published
- Max output: not published
- Open weights: no
- Licence: proprietary

## Where it stands

- Newer video generation models in the registry since its release: 17. The 5 newest:
  - Gemini Omni 1.2 Flash (2026-11-05) https://postcutoff.com/m/gemini-omni-1-2-flash/
  - FLUX 3 Max (2026-10-19) https://postcutoff.com/m/flux-3-max/
  - Kling 4.0 (and 4.0 Flash) (2026-10-15) https://postcutoff.com/m/kling-4-0/
  - Tavus Griffin (Human Interaction Model) (2026-10-01) https://postcutoff.com/m/tavus-griffin/
  - HeyGen Video 1 (2026-09-30) https://postcutoff.com/m/heygen-video-1/
- After it from Runway: Runway Aleph 2.0 (2026-05-21) https://postcutoff.com/m/runway-aleph-2/
- Closed weights; access is hosted only.

## What stands out

- #1 on Artificial Analysis text-to-video at launch: Launched as the top model on the Artificial Analysis Text-to-Video leaderboard (1,247 Elo), with better physics (liquids, momentum, collisions). Source: https://runway.com/research/introducing-runway-gen-4.5
- HDR and professional output formats (found after launch): API can output ProRes, PNG/EXR sequences, 10-bit SDR and HDR10/HLG/ACEScg masters (Gen-4.5 only for HDR). Source: https://docs.dev.runwayml.com/guides/models/

## Notes

Announced 2025-12-01; added to Runway API 2026-02-10 (text-to-video and image-to-video, 2-10 s). Cheaper sibling gen4_turbo (5 credits/s). gen4_aleph and gen3a_turbo removed from API 2026-07-30. Requires header X-Runway-Version: 2024-11-06.

Runway's flagship text/image-to-video model. Runway's API also resells third-party models (Veo, Seedance, etc.).

```bash
curl -X POST https://api.dev.runwayml.com/v1/image_to_video -H "Authorization: Bearer $RUNWAYML_API_SECRET" \
  -H "X-Runway-Version: 2024-11-06" -H "Content-Type: application/json" \
  -d '{"model":"gen4.5","promptText":"a drone shot over a misty fjord","ratio":"1280:720","duration":5}'
# poll GET https://api.dev.runwayml.com/v1/tasks/{id}
```

Sources: https://docs.dev.runwayml.com/guides/models/ , https://docs.dev.runwayml.com/guides/pricing/ , https://docs.dev.runwayml.com/api-details/api_changelog/ , https://runway.com/research/introducing-runway-gen-4.5

Model page: https://postcutoff.com/m/runway-gen-4-5/