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Reference image to influence the style or content of the output.
Seed unlocked - will use random seed
Edit Videos Online | AI Video Editor
Edit videos online with natural language. This online video editor lets you upload a short clip, describe the transformation you want, and generate a new version with updated style, lighting, environment, or objects. Designed for fast creative iteration, social media variants, and cinematic polish without re-shooting.
What is Runway Gen-4 Aleph?
Runway Gen-4 Aleph is an in-context video model built for comprehensive video editing and transformation. Instead of creating a video from scratch, the model takes an input clip and applies your instructions to modify it while preserving the original motion and temporal coherence. It can perform object manipulation, scene generation, environmental changes, and visual style shifts through text prompts or reference images.
The model excels at creative transformations that would normally require heavy compositing: adding or removing objects, changing locations or seasons, relighting scenes, or reshaping the overall tone. Because it reasons directly over your input footage, it keeps camera motion and subject movement consistent while applying the requested edits frame by frame.
Core Capabilities
Highlights from the official README for Runway Gen-4 Aleph.
Camera and Shot Generation
Generate new camera angles or extend shots while maintaining continuity. The model can create reverse shots, low angles, or medium shots from the same scene and preserve motion across frames.
- Novel view generation for alternate angles
- Shot continuation for seamless sequences
- Motion transfer from one clip to another
Object Manipulation
Add, remove, or replace elements inside a scene with matching lighting and perspective. This includes props, products, crowds, or background elements.
- Object addition with accurate lighting
- Object removal and cleanup
- Object replacement or retexturing
- Green screen style extraction
Environmental and Atmospheric Changes
Modify location, season, and weather without re-shooting. Shift a sunny field into snowfall, add rain, or adjust the time of day for a different mood.
- Location and environment modifications
- Weather effects like rain or snow
- Lighting updates for dawn, dusk, or night
Visual Style and Appearance
Apply stylistic transformations while preserving motion and structure. Use reference images to match a specific look, or describe style changes directly in the prompt.
- Style transfer using reference images
- Character appearance adjustments
- Color modifications and relighting
Technical Specifications
Gen-4 Aleph is a model built for in-context video editing and transformation. It processes a short input clip and outputs a modified video with consistent motion and lighting.
- Input: MP4 or WebM video, maximum 16MB
- Only the first 5 seconds of the input video are used
- Supported aspect ratios: 16:9, 9:16, 4:3, 3:4, 1:1, 21:9
- Prompt-based editing with optional reference image
- Optional seed parameter for reproducible variations
- Output: edited video with temporal consistency and coherent lighting
How to Edit Videos Online
A streamlined workflow to edit video online with AI.
1. Upload a Clip
Choose a short MP4 or WebM clip (up to 16MB). Stable footage with clear subjects yields the best results.
2. Describe the Edit
Write a concise prompt describing the change you want: lighting, environment, style, or object edits.
3. Generate and Iterate
Review the output, tweak the prompt, and iterate. Optionally add a reference image to guide style or content.
Prompting Guide
Good prompts are specific, visual, and concise. Focus on the transformation rather than describing the entire scene. Mention the changes you want while preserving important elements that must stay consistent.
- Start with the main edit: "make it winter" or "add soft cinematic lighting"
- Specify objects to add or remove: "remove the crowd" or "add neon signs in the background"
- Use reference images when you need a precise style or texture
- Keep prompts short and focused to avoid conflicting directions
- Iterate with small changes rather than large prompt shifts
Popular Use Cases
Use AI video editing to iterate faster and keep creative output consistent.
Creative Style Changes
Transform existing footage into a new look: vintage film, neon cyberpunk, or soft pastel moods. Use simple prompts to shift the overall aesthetic without re-shooting.
Product & Brand Updates
Refresh product shots or brand visuals while keeping the original subject. Swap backgrounds, colors, or lighting to match seasonal campaigns and new creative direction.
Social Media Iterations
Create multiple variants of the same clip for TikTok, Reels, and Shorts. Change style, mood, or environment to test which version performs best.
Cinematic Enhancements
Add atmosphere, weather, and dramatic lighting to raw footage. Emphasize cinematic tones while maintaining continuity and natural motion.
Location & Season Swaps
Turn a sunny day into snowfall, or shift a scene into golden hour. Modify environments while keeping subjects and motion consistent.
Object Edits & Cleanup
Add, remove, or replace objects inside a video with natural lighting and perspective. Clean up unwanted elements or insert new props quickly.
Limitations and Best Practices
Results depend on input quality, scene complexity, and the scope of your request. Heavily detailed scenes or extremely large changes can reduce fidelity. For the best outcome, use stable footage, clear subjects, and a focused prompt. If the output is close but not perfect, refine the prompt rather than rewriting it completely.
Gen-4 Aleph is also subject to model training constraints and algorithmic boundaries. Some transformations may be limited by data coverage or safety constraints. When you need exact control, iterate with smaller edits and use reference images to lock in key visuals.
Frequently Asked Questions
Everything you need to know before editing with AI.