Video Editor

Turn screenshots, clips, captions, and hooks into short app promo videos.

Make a Video That Shows the App

Video Editor brings screen recordings, 3D devices, text, narration, subtitles, and other media together into one timeline. You can use it for a quick feature demo or build a more polished promo with several scenes.

Open it from the welcome screen or Marketing. You don't need to learn every single control before making something useful. Start with one thing your app does well and show it clearly.

Make Your First Short Demo

1. Choose the document size for the place you'll share the video. Portrait is a good starting point for vertical social posts.
2. Add a screen recording as a file, or add a Device clip and set your recording as its screen content.
3. Trim the clip so it starts close to the useful action. Add a short text label if the benefit isn't obvious from the screen alone.
4. Add narration or record your own voice, then turn on subtitles if you want the explanation to work with the sound off.
5. Play the whole sequence, check the timing, and export a draft to watch outside the editor.

For example, a meal-planning app could show someone choosing meals and generating a shopping list. You don't need to walk through every settings screen for that benefit to make sense.

If you'd like help finding an opening idea, Video Hook Generator can prepare a script and starting video project. The sections below explain how to polish it.

The Big Picture

Each video is saved as a .ksvideo document package, so the timeline, imported media, embedded assets, narration audio, and waveforms all stay together as one Finder item.

• The window has a live preview, a multi-track timeline, and an inspector.
• The inspector changes depending on what's selected: document settings, clip controls, text, audio, narration, and animations.
• Projects run at 30fps internally, which keeps trimming, snapping, freeze frames, subtitles, and export timing predictable.
• The timeline starts with multiple tracks and tries to avoid clip overlaps when you add or import media.

Start With The Document

Set the document size first, because it affects preview framing, stock media orientation, device placement, subtitles, and export defaults.

• Social sizes include portrait 1080x1920, square 1080x1080, 1080p, 720p, and 4K.
• App Store Connect sizes include iPhone, iPad, macOS, and Vision Pro formats.
• Backgrounds can be solid colors or top-to-bottom gradients.
• Portrait projects can show TikTok or Instagram preview overlays so you can avoid covered captions and buttons.

Adding Media

Use the Add button to build the video from all sorts of app-marketing pieces, not just raw video files.

• Device: adds a rendered device clip you can move, scale, rotate, animate, and fill with screen content.
• File: imports images, videos, videos with transparency, and audio files. Multiple files are placed one after another from the playhead.
• Narration: generates AI voiceover from text and inserts it as a waveform-backed clip.
• Recording: records from your microphone, lets you preview or re-record, then inserts the audio as a normal recording or as a narration clip with subtitles.
• Shape: adds callouts such as rectangles, circles, capsules, arrows, triangles, hexagons, octagons, and stars.
• Arrow: adds a curved arrow clip with editable start, curve, end, color, line style, thickness, arrowheads, and draw amount.
• Stock Media: searches Pexels photos or videos and inserts whichever result you pick.
• Text: adds editable text with font, alignment, color, Markdown bold/italic support, and optional background styling.
• App Store Badge: adds a download badge you can position and size as part of the scene or closing call to action.

Device Clips

Device clips are handy when a flat screen recording feels too plain. Add a Device clip, then use the Clip inspector's Device section to pick the model and set screen content.

• Device clips render as movable, scalable, rotatable objects inside the canvas.
• You can set or replace screen content using an image or video file.
• You can remove screen content without deleting the device itself.
• You can reduce or remove device reflections when the default 3D render feels too glossy. If an older downloaded model doesn't expose the new reflection options, delete it and download it again.
• Device clips can use presets such as hero fade in, gentle push-in, parallax tilt, glide in, spin, feature focus zoom, and pull back.

The Timeline

The timeline is frame-based. Clips live on tracks, the playhead controls the preview, and you edit by dragging, trimming, splitting, and arranging clips.

• Press Space to play or pause.
• Use the rewind and fast-forward buttons to jump through the timeline.
• Use the zoom control, or press - and =, to zoom the timeline.
• Drag clips horizontally to move them in time and vertically to move them between tracks.
• Drag clip edges to trim. Media clips respect their source duration.
• Use marquee selection to grab multiple clips and move them together.
• Cut, copy, paste, and delete use the usual Edit commands.
• Press S to split the selected clip or selected clips at the playhead.
• Press F to create a one-second freeze frame when the selected clip supports it.

Snapping

Snapping helps clips and canvas objects line up cleanly.

• Timeline snapping lines clips up with other clip starts and ends.
• Canvas snapping shows guide lines while you drag objects around the preview.
• If a drop would overlap another clip on the same track, the editor rejects that placement rather than quietly breaking your timing.
• You can toggle snapping from the commands menu with Shift-Command-S.

Clip Styling

Select a visual clip and use the Clip inspector for the usual promo-video polish.

• Transform controls include scale, X/Y position, and X/Y/Z rotation.
• Style controls include opacity and corner radius.
• Shadow controls include color, radius, and X/Y offset.
• Crop controls trim the top, bottom, left, and right edges by percentage.
• Visual fade controls add fade in and fade out timing.
• Video and audio clips also have playback speed controls.
• Value entry fields have reset buttons so you can put individual settings back to their defaults without recreating the clip.

Animations

Animations are attached to individual clips and appear as editable blocks on the timeline.

• You can add a blank animation to most selected clips.
• Device clips also get richer presets for common app promo movements.
• Bounce Gentle, Bounce Medium, and Bounce Strong styles are available when a clip needs a more playful entrance or a bit of emphasis.
• Arrow clips can animate their geometry, color, thickness, and draw range, so callouts can trace toward the thing they're pointing at.
• Animation blocks can be moved and resized on the timeline.
• Selected animation settings show up in the inspector.
• When the playhead is inside an animation, some base clip controls are locked so you don't accidentally fight the animated value.

Narration

Narration is for getting a voiceover quickly without booking studio time. Add Narration, type the script, pick a voice, generate it, preview the waveform, then drop it into the timeline.

Try a short paragraph before generating a long script. Listen out for awkward phrasing and leave enough time for the screen action to match what's being said. A sentence that's easy to read isn't always easy to listen to.

For a custom voice, open Manage Voices and choose Create Custom Voice. Follow the recording prompt and preview the result before using it for narration. You can also record your actual voiceover directly if you'd rather perform the finished script yourself.

• The first use requires downloading narration models, around 3GB.
• A fast Mac is strongly recommended, roughly M3-class or better with 16GB RAM.
• You can edit an existing narration clip, regenerate it, and update the clip in place.
• Narration clips store audio data, waveform images, text, voice ID, and word-level timestamps inside the project.

Captions And Subtitles

Narration clips can generate subtitles from their word timing. Select a narration clip, open the Narration inspector, then turn on Show Subtitles. Video and audio clips can also become subtitle-ready narration clips by double-clicking the clip and enabling Use video speech as narration or Use audio speech as narration.

• Display modes include Word Stream, Sentences, and Phrases.
• Karaoke highlighting is available for sentence and phrase modes.
• Karaoke styles include fade, sliding underline, sliding background, and pulse.
• Subtitle transitions include none, fade, slide up, and pop.
• Position controls include top, center, bottom, left/center/right alignment, and a Social Safe Area toggle.
• Subtitle styling includes font, size, text color, karaoke color, background, padding, corner rounding, stroke, and shadow.

Custom Audio Recordings

Recorded microphone audio can become a subtitle-ready narration clip. After recording, enable narration subtitles, let Kickstart transcribe the audio, tweak the transcript if needed, then insert the recording with word timing for subtitles.

• Use a plain recording when you just need audio on the timeline.
• Use a narration recording when the clip needs subtitle controls, karaoke highlighting, or word-level timing.
• You can re-record, re-transcribe, and update an existing recording-backed narration clip.

Audio

Audio clips, video clips with audio, and narration clips all get Audio inspector controls.

• You can mute individual clips.
• Volume can go from silent up to boosted levels.
• Fade in and fade out are available up to 10 seconds.
• Track mute controls let you compare versions without deleting anything.

Previewing

The preview shows the current playhead frame using the document size, background, visible tracks, active clips, subtitles, device renders, and social overlays.

• Hidden tracks don't show up in the visual preview.
• Clicking the canvas clears the current clip selection.
• Use social overlays before export. It's much easier to fix covered captions before rendering.

Stock Media

Stock media comes from Pexels through Kickstart's media endpoint. It's great for backgrounds, b-roll, or context around app footage.

• Search photos or videos from the Stock Media sheet.
• Video results can be filtered by landscape, portrait, or square orientation.
• Cards show creator, duration or dimensions, and video quality where available.
• Selected media can be inserted directly onto the selected track at the playhead.
• The sheet includes Pexels usage guidance and a copyable attribution line, even though Pexels doesn't require attribution.

Exporting

Use Command-E or Export Video to render an MP4. Export is frame-by-frame, so the output should match the preview closely.

Your saved project stays editable; the exported movie is the file you'll share or upload. Watch that file at least once before publishing it, especially to check small text, audio levels, and whether the opening gets to the point quickly.

• Resolution presets include Match Document, 720p, 1080p, 4K, Square 1080, Portrait 1080, and Custom.
• Video bitrate presets range from 3 Mbps to 50 Mbps.
• Audio bitrate presets range from 128 kbps to 320 kbps.
• Standard exports use HEVC video and AAC audio in an MP4 file.
• Projects with transparent backgrounds export as QuickTime movies so the transparency survives.
• The export dialog remembers the last output filename and location where possible.
• During export, Kickstart shows progress and lets you cancel.
• After export, you can reveal the finished file in Finder.

Saving A Still Frame

Use Save Frame as Image to export the current preview frame as a PNG. The default filename includes the current timecode, which is useful for thumbnails, social images, or quick App Store artwork drafts.

Practical Tips

• Pick your document size before importing lots of assets.
• For TikTok or Reels clips, use Portrait 1080 and turn on the TikTok or Instagram preview overlay early.
• Keep narration clips on their own track. It makes subtitles, waveform timing, and audio fades easier to reason about.
• Use device clips for hero moments, then reach for shapes or text clips for short callouts.
• Use freeze frame when an app screen needs to pause while the voiceover catches up.
• If an imported clip lands later than expected, check whether the selected track already had an overlap.
• Use Match Document for most exports. Switch to custom sizes only when a platform asks for something different.
• For quick drafts, keep bitrate around Medium. For final promo videos with lots of motion, use High or Very High.