Frame-accurate annotation
Drawings are tied to the exact frame being viewed, with the video and canvas using the same frame clock so marks do not drift while scrubbing.
FrameSketch
FrameSketch is browser-based video annotation software for animators who need to draw, add notes, and review footage frame by frame. It keeps video files on the user’s device, with optional syncing for annotations and project metadata.
FrameSketch for frame-by-frame video annotation
FrameSketch is browser-based video annotation software for animators. It places a drawing canvas over locally loaded footage so users can step through frames, mark arcs and poses, add notes, and review a selected range without moving the video to a server.
The app supports projects with multiple scenes, layers, comments, guides, grids, and adjustable video visibility. Work is saved locally as it is created and can be exported as a compact .fsk project file. Optional cloud sync transfers annotations and project metadata between devices, but requires the video to be selected locally on each device.
Frame-by-frame tools for shot review
Onion skin
See frames before and after the current frame through adjustable ghosting, helping you assess movement, arcs, and poses.
Layered drawing workspace
Organize brush strokes, shapes, and notes into layers that can be reordered, renamed, recolored, hidden, or adjusted for opacity.
Review and drawing tools
Use brush presets, an eraser, laser pointer, geometric shapes, text labels, sticky notes, and comment markers. Pen pressure is supported when the device provides it.
Portable project files
A project stores scenes, drawings, notes, comments, and settings in one compact .fsk file. Projects can be exported, emailed, stored, or optionally password-protected.
Local-first workflow with optional sync
Work locally in the browser or PWA. Optional cloud sync carries annotations and project metadata across devices, while the video remains on the original machine.
Practical animation and review workflows
Animation blocking and motion analysis
Step through a shot, draw motion arcs and breakdown marks directly over the footage, and use onion skin to compare neighboring frames.
Shot feedback and review
Pin notes, labels, and comment markers to exact frames so feedback remains attached to the relevant pose or action.
Scene and pose checking
Use layers, grids, rulers, guides, and adjustable video visibility to inspect composition, alignment, staging, or key details in a scene.
Hand-off of annotated shots
Export a compact .fsk file containing the annotation work, then email or store it for another person to open and continue editing.
Private or offline annotation
Load footage locally, work offline through the PWA, and keep annotations on the device when projects contain sensitive or private video.
Pros and Cons
Pros
- Runs in modern browsers without a traditional installation and can be installed as a PWA for offline access.
- Keeps video files local and does not re-encode or upload them.
- Provides frame-accurate strokes, onion skin, layers, notes, comments, and review-oriented drawing tools.
- Exports complete projects as compact .fsk files that can be shared and optionally password-protected.
- Core studio features are free to use; free accounts can sync up to three projects.
Cons
- An account is required to use the app, although cloud sync can be disabled and local work can remain on the device.
- Video playback depends on browser codec support and local hardware; very large files may stutter on older machines.
- Synced projects do not include the video, so the source footage must be re-selected on another device.
FAQ
Do I need to install FrameSketch?
No installation is required. FrameSketch runs in modern Chrome, Edge, Firefox, or Safari. It can also be installed as a progressive web app for offline, app-like use after the app has been opened once.
Do I need an account?
Yes. An account is required to use the app. You can sign up with an email address and password or continue with Google; email sign-up requires verification.
How do I start a frame-by-frame annotation?
Create a project and scene, load a video file from your computer, choose a drawing tool, and annotate the footage frame by frame. Use the arrow keys to move between frames and enable onion skin to see surrounding frames.
Which video formats does FrameSketch support?
FrameSketch reads local video files through the browser and does not upload or re-encode them. It supports formats the browser can decode, including MP4 with H.264, MOV, M4V, and WebM. H.264 MP4 is recommended when a file does not play.
How can I save or share an annotated project?
You can export a project as a single .fsk file containing its scenes, layers, strokes, shapes, notes, comments, and settings. Exports can optionally be password-protected, and the file can be sent to another person to continue editing.
Quick Facts
- Category
- Video annotation software
- Primary users
- Animators and shot-review teams
- Platform
- Modern web browsers; installable PWA
- Video handling
- Local browser playback; footage is not uploaded or re-encoded
- Project format
- .fsk project file
- Core access
- Free to use; free accounts can sync up to 3 projects
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