EbSynth
EbSynth is browser-based VFX software that spreads a single painted keyframe across an entire shot. Artists use it for hand-drawn animation, retouching, digital makeup, colorization and rotoscopy, with an optional AI keyframe generator.
What is EbSynth?
EbSynth is VFX software that runs in the browser and is built around a single gesture: you change one frame, and the change travels across the whole shot. You supply a guiding video, meaning the footage you actually filmed, plus one or more keyframes painted over it. EbSynth computes optical flow from the guiding video and propagates the appearance of your keyframes over the rest of the sequence. What sets it apart is stated bluntly in the vendor's own FAQ: the propagation is not AI. It is a texture-synthesis algorithm that draws only on your video and your keyframes, with no generative model trained on external datasets. That technical choice carries a legal consequence the terms spell out, because no pre-trained model touches the image, the ownership status of your output video is unaffected. One optional feature does use AI: Generate Image runs SDXL 1.0 to produce keyframes for you, and using it places the finished video under the SDXL license. Three uses are put forward. Painting over video turns a filmed performance into hand-drawn animation. Retouching and colorizing covers video touch-ups, digital makeup and colorization without manual tracking. The third is simply speed: results come back fast enough to keep iterating without leaving the creative flow. The tool is desktop only, and a modal blocks phones and tablets outright. Chrome is recommended, especially for long or high-resolution projects, and on a laptop you are advised to make sure the browser uses the dedicated graphics card. A ten-minute tutorial on the home page walks through the whole workflow. Behind it is Secret Weapons, Inc., registered in Dover, Delaware and described on its own site as a VFX research lab. EbSynth is its first product, created by Czech developers Ondřej Jamriška and Šárka Sochorová. Their stated ambition is to put effects once reserved for large studios within reach of small teams and independent artists.
What it does
- Propagate a single painted keyframe across an entire shot
- Turn a filmed performance into hand-drawn animation
- Retouch footage and apply digital makeup without manual tracking
- Colorize a whole shot from one colored frame
- Handle rotoscopy on isolated elements with alpha-channel keyframes
- Generate keyframes with the built-in SDXL image feature
- Export to MP4, or to a PNG sequence up to 4K
When to use EbSynth / When not to
A quick filter to help you decide if EbSynth is the right fit.
When to use EbSynth
- VFX artists and compositors who need a stylized look carried across a shot without frame-by-frame tracking
- 2D animators and illustrators who would rather paint one frame well than redraw a whole sequence
- Independent filmmakers and small creative teams, the audience Secret Weapons says it builds for
- Video editors and colorists handling retouching, digital makeup or colorization on short shots
- Studios under strict confidentiality constraints, who can run the Studio tier entirely offline
When not to use EbSynth
- Anyone working from a phone or tablet: the app blocks non-desktop devices outright
- Teams that need to call the tool from a pipeline, since there is no public API and no developer documentation
- Users after end-to-end text-to-video generation, because EbSynth transforms an existing shot rather than creating one
- Footage shot with hard shifting shadows, flat shiny fabrics or heavy motion blur, where tracking quality collapses
- Organizations that require a signed DPA or formal security certifications, none of which are published
How to use EbSynth
A typical end-to-end flow, from setup to results.
- Open the app in Chrome on a desktop machine and create an account with your email address
- Import the guiding video, the shot you filmed and want to transform
- Pick the frame that shows the most content in a clear, settled pose, avoiding the middle of a movement
- Paint your keyframe over that frame, keeping its shapes aligned with the shapes of the video frame
- Or generate the keyframe with the built-in Generate Image feature instead of painting it
- Split the shot into parts that move independently, such as background, face and eyes, and give each its own video track
- Use keyframes on a transparent background, with an alpha channel, when only isolated elements should change
- Run the propagation and review the synthesized frames
- Add keyframes where the result breaks, or roughly repaint AI artifacts and run a second AI pass at lower strength
- Export the result as MP4, or as a PNG sequence up to 4K on the Pro plan
Pros & Cons
Pros
- You keep full copyright of the output: the synthesis uses no AI and no pre-trained model, so ownership is unaffected
- The free plan is permanent, with no time limit and no functional limit, so the whole tool can be tried
- Projects are not stored online, and render media is deleted from the server as soon as the result comes back
- The vendor states plainly that customer data is never used to train AI models
- No analytics or marketing cookies, and no card details reach the vendor, since Stripe handles payment directly
- The Studio tier runs entirely offline for teams working under confidentiality constraints
- Working method is documented on the site itself, from keyframe timing to how to shoot the guiding video
Cons
- Desktop only: a modal blocks phones and tablets, and no mobile app exists
- No public API and no developer documentation; command-line automation exists only in the Studio tier, whose price is not published
- Results depend heavily on the shoot, as hard shifting shadows, flat or shiny fabrics and motion blur all degrade the propagation
- Keyframe shapes that do not match the video frame produce stretchy, ripple-like artifacts
- AI-generated keyframes place the entire output video under the SDXL 1.0 license
- No refunds on fees already paid, and access can be terminated at any time, with or without cause or notice
- No DPA, no Article 27 EU representative and no published security certification
Pricing & Plans
A permanent free plan is available at no cost, covering all core functions with 720p HD video export and MP4 output. The cheapest paid entry point is the Pro plan at USD 20.00 per month, which adds export up to 4K, PNG sequence output, 100 generated images and priority processing. A Studio tier is offered on quotation only. Displayed prices exclude any applicable sales tax, and no refund is issued on fees already paid.
- Free — USD 0
- Pro — USD 20 per month
- Studio — custom pricing
- on quotation
Data, GDPR & hosting
A consolidated view of how EbSynth handles your data.
GDPR overview
EbSynth's GDPR position is real but partial, and stated in passing rather than in a dedicated section. The terms invoke the regulation once, alongside COPPA, to justify the minimum age of thirteen. The privacy policy, effective 22 August 2025, does list GDPR-style rights: access, rectification, erasure, restriction or objection, portability, withdrawal of consent, and the right to lodge a complaint with a supervisory authority, all exercised by writing to hello@ebsynth.com. International transfers are acknowledged, since data may be processed outside your country of residence, including in the United States, with the company relying on safeguards implemented by Clerk and Stripe. What is missing says as much: no Article 27 EU representative is designated, no data protection officer is named, and no data processing agreement is published or offered.
Who owns the data?
The terms are unusually direct on ownership. You keep full copyright of the videos you create, provided you own the copyright to the guiding video and the keyframes you feed in. Secret Weapons states that it neither accesses nor claims ownership of users' input and output media, and disclaims liability for any misuse of copyrighted material by users. Because the synthesis step uses no AI and no pre-trained model, the vendor argues it cannot affect the ownership status of the output video. One exception matters: if you generate keyframes with the built-in AI feature, the whole finished video falls under the SDXL 1.0 license.
Reuse rights
Outputs are yours to reuse without asking. Nothing in the terms requires permission, attribution or a license back to Secret Weapons, and no clause restricts commercial use, as long as you hold the rights to the material you put in. The single caveat is AI-generated keyframes, which pull the finished video under the SDXL 1.0 license. On the vendor's side, your video and keyframes are uploaded only to render the shot and are deleted from the server as soon as the result reaches your browser. Your email address is used to authenticate the account and to send important service notices; IP address, browser type and device information are collected for security and operational purposes only, never for marketing or analytics. Payment details go straight to Stripe, which the company says it never receives or stores. The privacy policy, effective 22 August 2025, states plainly that none of this material is used for AI training and that nothing is sold or shared with advertisers.
Data retention & training
Hosting summary
EbSynth does not name a hosting country for its rendering servers. The only geographic statement in the privacy policy concerns transfers: your information may be processed in countries outside your country of residence, including the United States, where data protection laws may differ. The company says it relies on the safeguards implemented by its two named third parties, Clerk, which processes and stores account email addresses, and Stripe, which handles payment. The domain itself resolves to a Cloudflare anycast address, which says nothing about where processing actually happens. The practical point is that the material you work on is not hosted in the usual sense at all: the guiding video and keyframes are uploaded solely to render the animation and are deleted from the server as soon as the result reaches your browser, while projects otherwise remain on your own machine. The Studio tier removes the question entirely by running offline, with no upload.
Things to keep in mind
Risks and trade-offs to weigh before adopting EbSynth.
- The AI label is misleading here, since the propagation is algorithmic: buying EbSynth expecting end-to-end AI video generation will disappoint
- Generating keyframes with the built-in AI feature places the entire output video under the SDXL 1.0 license, which is worth checking against commercial plans before shipping
- Painting convincingly over a shot remains a craft skill; the software removes the tracking work, not the drawing, and the learning curve sits in keyframe choice and alignment
- The vendor may end your access at any time, with or without cause and without notice, and no refund is due on what has already been paid
- The service is provided as is, with no guarantee of availability or freedom from errors, so a delivery deadline should not rest on it without a fallback
- Retention beyond the immediate deletion of render media is not quantified, and there is no DPA or Article 27 EU representative to lean on
- Realistic retouching and digital makeup on real people are easy to push too far; making convincing alteration of footage cheap is a responsibility as much as a feature
Setup & Integrations
Technical difficulty
Setup is trivial; the craft is not. There is nothing to install, the app opens in the browser, and an account with an email address is all that is required. Chrome is recommended, especially for long or high-resolution projects, and on a laptop you should check that the browser uses the dedicated graphics card, since processing is memory-intensive. The real learning curve is method: choosing and timing keyframes, aligning shapes, splitting a shot into tracks, and shooting the guiding video well. A ten-minute tutorial covers the workflow.
Deployment
Behind EbSynth
Social
Resources
All the official URLs gathered for verification and reference.
Frequently asked questions
Does EbSynth actually use AI?
Who owns the videos I create with it?
Is there a genuinely free version?
Are my files stored on EbSynth servers?
Can I use EbSynth on a phone or tablet?
Is there an API for automation?
How do I cancel a paid subscription?
Is there a minimum age to use it?
Should you pick EbSynth?
EbSynth does one thing, and the narrowness is deliberate. You paint a frame, the software carries it across the shot, and you iterate until the result holds. Two things make it unusual among tools filed under AI. The core is not generative: propagation is texture synthesis working from your own footage, which is why the terms can state that ownership of your output is unaffected. The second is the privacy posture, with media uploaded only to render, deleted immediately, never used for training, and no analytics or marketing cookies at all. The trade-offs are just as clear. There is no mobile version and no API, and the Studio tier that would let a business automate the tool offline is priced on request only. Contractually the vendor gives itself room: no refunds, termination at any time without cause, service delivered as is, arbitration in Delaware, and neither a DPA nor a security certification published. Output quality also depends on decisions made before the software is even opened, since lighting, fabric texture and frame rate all shape how well the propagation tracks. For VFX artists, animators, editors and small independent teams, the honest test costs nothing: the free plan has no time limit and no functional limit, so the whole tool can be judged on a real shot before any money changes hands. For anyone needing integration, mobile access or formal compliance paperwork, the answer will be shorter.
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