Scientific process
How a vaccine trains the immune system
A harmless fragment arrives, a cell picks it up, and the body builds a response it can repeat later. Three shots, in that order.
Check with: a clinician or biology teacher
Concept to explainer video
Free AI Explainer Video Generator
Describe a concept in one sentence. The agent writes the script, splits it into shots, generates each shot, and adds a voiceover with captions — a short explainer you can drop into a lesson, a training deck or a product page.
Free to start: sign up and your daily credits cover the first drafts. Video generation is for Pro users, and every shot spends daily credits.
The sample, end to end
Seventeen seconds, three shots, one voiceover.
Photosynthesis, explained to someone who has never seen inside a leaf. This script was written before anything was generated; each line became one shot.
Shot 1 · 5s
“A leaf looks still. Inside, it is a factory.”
Shot 2 · 6s
“Light hits the chloroplasts, and they turn it into sugar.”
Shot 3 · 6s
“The sugar travels down the vein to the rest of the plant. That is photosynthesis.”
Captions are burned into the sample. The narration is an AI voice reading the script; rewrite a line and only the shot it belongs to has to be regenerated.
- 4–15 s
- per shot, three to six per explainer
- 768P → 2K
- draft cheap, finish the keepers
- Voice + captions
- read from the same script
- 16:9 · 9:16 · 1:1
- lesson, phone, feed
Definition
An explainer video shows the order, not just the parts.
A paragraph about photosynthesis lists the parts. A short video shows light entering the leaf, chloroplasts turning it into sugar, and the sugar leaving through the vein. Input, transformation, output — the order is what makes a concept land.
The renders come after the script, not before it. A wrong step costs one line to fix instead of a whole re-render, and the caption text is already written when the shot arrives.
How it is made
Describe. Script. Generate. Review.
01
Describe the concept and the audience
One sentence plus who it is for: “Explain photosynthesis to a 12-year-old in fifteen seconds.” The audience decides how much can be left out.
02
The agent writes the script and splits it into shots
One narration line per shot, in viewing order. If a line needs an “and”, it is two shots — split it before generating.
03
Each shot is generated, then voiced and captioned
The line becomes the shot's visual prompt: subject, camera move, light, length. The voiceover reads the script, and the captions put the same words on screen.
04
Watch it, fix one shot, export
Ask for one change at a time — a slower push-in, warmer light, a longer hold — regenerate only the shot that needs it, then export at the resolution you need.
What people explain with it
Six concepts a paragraph cannot carry.
Each of these has a shape a viewer can follow once it is moving. The check line names who should watch the result before it ships.
Natural phenomenon
Why the sky turns red at sunset
The sun is low, so light crosses more air; short blue wavelengths scatter away and the long red ones reach your eye. One beam, one horizon.
Check with: a physics teacher
Economic mechanism
Why prices rise when demand climbs
More buyers reach for the same crate; the coin pan sinks and the price climbs. The balance scale makes the trade-off visible.
Check with: an economics editor
Abstract idea
What compounding does to a small habit
A small daily gain stacks into a tower that dwarfs the first coin. The metaphor carries the maths the viewer would not sit through.
Check with: whoever owns the claim
Workflow or system
Where a support ticket goes after it is sent
Ticket in, queue, owner, reply. One shot per hand-off, so the viewer sees where their request actually waits.
Check with: the support lead
Timeline or causal chain
How one late delivery empties a shelf
Truck late, stock short, shelf empty, customer leaves. Each shot is one link in the chain, and the chain is the explanation.
Check with: the operations team
Three prompts to start from
Copy one, change the subject, keep the camera directions.
These are shot prompts, not full scripts. Paste one into the agent's prompt box and edit the subject; the style sentence at the end is what keeps shots cutting together.
Photosynthesis
Light becomes sugar inside a leaf. The cutaway shows the chloroplasts doing the work and the vein carrying the result away.
Shot prompt
Inside a single green leaf, seen in cutaway on a dark studio background: golden sunbeams enter from the upper left, chloroplasts light up one after another like glowing green beads, and golden sugar molecules assemble and travel down the central vein toward the stem. Slow push-in that becomes a gentle orbit. Cinematic 3D render, shallow depth of field, dust motes in the light beams. No text, no labels, no watermark.
Why the sky is blue
Blue light scatters in every direction while red and orange pass straight through — one beam splitting above the sea.
Shot prompt
View from just above the ocean at noon: a wide beam of white sunlight streams toward the horizon and splits in the air. Blue light scatters outward across the whole sky like ink blooming in water while red and orange pass straight through toward the sea. Camera drifts slowly upward through the beam, glowing specks of air along its path. Photoreal, deep blue gradient sky, warm horizon. No text, no labels, no watermark.
Supply and demand
A price is a balance. More shoppers tip the coin pan, the crates rise, and the price climbs.
Shot prompt
A market stall at night under warm hanging lanterns: wooden crates of oranges sit in the left pan of a giant brass balance scale and a stack of glowing gold coins in the right pan. Shoppers gather at the stall, the coin pan sinks, the orange crates rise, and the coins multiply and glow brighter. Camera circles the scale at waist height, shallow depth of field, soft haze. No text, no labels, no watermark.
Where it fits
Three places a short explainer does the work of a page.
Anywhere someone has to picture a process they cannot see.
Course lessons
Open with the mechanism
Play the clip before the term appears. Students then have something to attach “chloroplast” to.
Training and onboarding
Walk a process step by step
One shot per hand-off, each short enough to sit inside a checklist or an LMS module.
Product explanations
Show what changes for the user
Before, the action, after — with a voiceover that says what the screen does not.
The hard part is the script, not the render
A concept that is obvious to the person who owns it is usually invisible to everyone else. The first draft of the script is where that gap shows up: write the sentence, read it aloud, and cut whatever the shot already says.
Before it ships
Three checks, three boundaries.
What to look at before you publish, and what the render cannot do at all.
The three checks
01
Is the order right?
Watch once with the sound off. If the steps do not read in sequence as pictures, the script is wrong and no amount of re-rendering will fix it.
02
Are the scale and the anatomy right?
A chloroplast in the wrong place, a molecule moving upstream, a scale with the pans reversed. Have the subject owner watch it once.
03
Does the narration match what is on screen?
Read the captions against the frames. A line playing over a shot it was not written for is the most common defect in a fast edit.
The three boundaries
01
No typeset formulas, charts or arrows
The model renders scenes, light and material — not crisp text, equations or labelled diagrams. Add those in an editor after export if the concept needs them.
02
One clip is 15 to 60 seconds, not twenty minutes
Each shot runs 4 to 15 seconds. A longer lesson is several explainers, each covering one mechanism, cut together in your editor.
03
It does not know your subject
The model will picture whatever the script says — including a wrong claim — with full confidence. The subject owner signs off, not the tool.
How it compares
Different tools, different failure modes.
Explainer video is a crowded category. What separates the options is what they can put on screen.
Approach
What you get
Where it stops
Felo concept explainer
What you get
Generated footage with a script, voiceover and captions, from a sentence
Where it stops
No typeset diagrams, formulas or on-screen labels
Diagram and whiteboard tools
What you get
Crisp arrows, boxes and labels that stay legible at any size
Where it stops
Nothing moves that you did not animate by hand
Avatar presenter tools
What you get
A person-shaped presenter reading your script
Where it stops
The presenter is the visual; the mechanism still needs footage or a diagram
Slide-to-video tools
What you get
Your existing slides with timing and a voice track
Where it stops
Only as clear as the slides already are; no motion inside a concept
Cost of the sample above
Three shots, drafted cheap, finished at 2K.
At the current rates a second of video costs 86 credits at 768P and 138 at 2K. The sample above runs seventeen seconds, which is 1462 credits at 768P, about $1.46; redoing one six-second shot at 2K costs another 828 credits, about $0.83.
Rates are limited-time offers and use roughly 1000 credits ≈ US$1. Check your workspace for the current price.
See the full rate table on the AI Video Generator page.Explainer video FAQ
Questions about explaining a concept with video
What is a concept explainer video?
A short video that shows how something works, in the order a viewer needs it: what goes in, what changes, what comes out. This workflow takes your concept as a sentence, writes it as a script, and generates one shot per line.
How is this different from a normal AI video generator?
A single prompt gives you one scene. An explainer needs a sequence: several shots that follow one another, a voiceover that names the steps, and captions that match. The agent writes that sequence before it renders anything, so a wrong step is a one-line fix instead of a whole re-render.
What can I give it as a starting point?
A sentence, a paragraph of notes, or a page URL. The more explicit the audience, the better the script: “explain this to a new hire” produces a different first line than “explain this to a customer”.
Does it add a voiceover and captions?
Yes. The script the agent writes is also the narration, read by an AI voice, and the same lines appear as captions timed to the shots. You can rewrite any line and regenerate only the shot it belongs to.
Can it draw formulas, diagrams, charts or arrows?
No. It generates footage of scenes, not typeset graphics. Equations, labelled diagrams and precise arrows belong in an editor after export — or in a diagram tool if they are the point of the video.
How long can an explainer be?
Each shot runs 4 to 15 seconds, and one explainer is usually three to six shots — 15 to 60 seconds. A longer lesson is a series of explainers, each covering one mechanism.
Which aspect ratio and resolution should I use?
16:9 for a lesson or a slide deck, 9:16 for a phone-first clip, 1:1 for a feed. Draft at 768P, then regenerate the shots you keep at 2K.
How do I keep the style consistent across shots?
Repeat the same style sentence in every prompt — lens, light, palette — and keep the same model and ratio. For a shot that has to start where the previous one ended, use the first and last frame mode.
Who should review the video before it is published?
The person who owns the subject. Watch it once with the sound off to check the order, then once with sound to check that the narration matches the frames. Generated footage can be confidently wrong.
Who can use it, and what does a shot cost?
Video generation is available to Pro users, and every shot spends daily credits: 86 credits per second at 768P and 138 at 2K at the current rates. Check your workspace for the options on your account.
Is there an explainer video maker that writes the script for me?
This one does. An explainer video maker usually starts from a template or a slide deck you already have; here you start from one sentence and the agent writes the narration line by line, splits it into shots, and renders each shot with the voiceover and captions already attached. Draft at 768P, keep the shots that carry the explanation, and regenerate only those at 2K.
Discover more
Other ways to make a video with Felo.
AI Video Generator
Want one cinematic scene instead of a sequence? Describe a single shot and get a few seconds of footage.
Image to Video
Need the same frame to move? Start from a still and animate it, keeping the photo as the first frame.
More slides and video tools
Explain one thing well.
Write the concept as one sentence, let the agent split it into shots, and watch the first version. A few shots are enough to see whether the explanation carries.
Free to start. Video generation is for Pro users.