03
Adding Assets
You combine seven types of assets on the timeline: images, audio, video, text, emoji/kaomoji, handwriting, and effects. Register frequently used objects as favorites so you can reuse them across other projects too.
Supported Formats
- Images — PNG, JPG, WEBP. Transparent PNGs (with alpha channel) are supported too, so you can use character art and overlays
- Video — MP4 (H.264) / WebM (VP9). Imported as a silent looping video that works like a moving illustration (see "Adding video material" below for details)
- Audio — MP3, WAV, AAC. Works with large audio files over 30 MB. Besides adding files, you can also record vocals or narration live with your microphone while your main audio plays back (see "Recording Audio with Your Microphone" below)
- Text — Enter lyrics, subtitles, or narration scripts directly into the app
- Emoji/Kaomoji — Choose an emoji or emoticon from a category and place it on the canvas. Lightweight because it doesn't add an image file. Like other text assets, it supports move, scale, rotate, and keyframe operations. Recently used stamps are saved to 'Frequently used' in the browser for easy reselection
- Handwriting — Draw in real time with a pen input device, mouse, or touch, and the strokes are recorded as-is. Choosing "With animation" records in sync with main audio playback, just like recording audio with your microphone. You can change the color, thickness, and line-cap shape of recorded strokes afterward (see "Handwriting Stroke Settings" below)
- Effects — Add particle effects such as rain, snow, petals/falling leaves, or confetti to the timeline. No file needed — just pick a preset (see "Adding Effect Assets" below)
Favorites
Right-click (or long-press) an object on the canvas and choose "Other ▶ Add to Favorites" to register it under a group name. Registered objects can be re-placed from the "Favorites" tab in the "Adding Assets" panel, filterable by group. The placement position is recalculated based on the canvas center and current playhead position, so you don't need to worry about the original position or timing. Favorited images, lyric blocks, and prose blocks have their asset data saved along with them in the browser, so they can be used across different projects too. Favorites are not saved in the project file — they are saved in your browser (device).
Adding Video Material (Silent Looping Video)
Add a video file (MP4 or WebM) from the "Video" tab to place it on the timeline as a silent, short looping clip — like a moving illustration. This is useful when you want to use footage with subtle motion instead of a static photo or artwork. Videos are limited to a maximum of 10 seconds; longer videos are automatically trimmed to the first 10 seconds. The audio track is automatically removed during import, so if you need sound as well, use "Extracting Audio from Video Files" below or add audio separately via the "Audio" tab. Note: iOS Safari does not support WebM (VP9), so if you need reliable playback on iOS, use MP4 (H.264) only.
Extracting Audio from Video Files
Add a video file (MP4 like an Android screen recording, or MOV like an iOS screen recording) via the "Audio" tab, and the app will discard the video part and extract only the audio track, importing it as a normal audio asset. You don't need to split it out in a video editor first. On your PC, you can drag and drop the file directly; on smartphones, use the file picker (file selection dialog) to select the file. If you want to use the video itself as a visual element rather than just its audio, see "Adding Video Material" above.
Recording Audio with Your Microphone
While your background audio is playing, you can record vocals or narration directly in your browser using your microphone. The browser automatically checks whether recording is supported, and if not, the recording button won't appear at all. Chrome, Edge, and Firefox all support this, as do Safari on iOS and macOS in MP4 format. Recorded audio is treated the same as other added audio assets for timing and layering. Like all assets in KiraNeiro, your recorded audio never touches our servers — it stays in your project.
About microphone connections
For recording, please use your computer's built-in microphone or a wired microphone instead of a Bluetooth (wireless) microphone. Bluetooth connections can be unstable, which may cause parts of the recorded audio to be dropped, resulting in a recording that is shorter than the actual time you recorded.
Adding Effect Assets (rain, snow, petals, confetti, and other particle effects)
From the "Effects" tab, just pick a preset — rain, snow, petals/falling leaves, or confetti — to add a particle effect to the timeline. There's no file to choose; it's placed immediately with default settings. After adding it, use the Properties panel on the right to adjust color, opacity, density (amount of particles), speed, size, jitter, and preset-specific details (such as the rain's angle or the snow's wind strength). Effects can be used as either a background or a foreground layer — there's no dedicated checkbox for this; instead, use the same layer-order controls as other objects (the right-click menu's "Bring to front" / "Send to back"). For example, you can layer falling snow in front of a character, or rain filling the whole background.
Handwriting Stroke Settings
When you add handwriting, you can choose between two drawing methods. "With animation" records in sync with main audio playback and reproduces the original stroke order and speed during playback. "Without animation" isn't synced to audio playback — it places the drawn line as a static image instead (this can't be switched after creation). Color, thickness, and line cap (round / square / butt) can be adjusted from the same settings dialog, whether as default settings before recording starts or as after-the-fact changes to already-recorded strokes. The dialog's "Randomize" feature can also suggest random combinations of color, thickness, and line cap.
Handwriting Stroke Animation Settings
Strokes recorded "with animation" can have their reveal motion changed afterwards. Right-click the object and choose "Motion ▶ Stroke Playback" to set two things: "Motion" (either "Draw" — the line is progressively drawn in — or "Erase" — the finished line is progressively erased away) and "Order" ("Original order" = exactly as recorded; "Reverse all" = it appears starting from the part drawn last; "Reverse stroke order" = each individual pen stroke is still drawn the way it was, but the pen strokes play in reverse sequence). The dialog has a live animated preview with a play button. Because long strokes take a while at normal speed, the preview speed can be set from 1x to 10x (this only affects the preview, not the finished work's playback speed). Strokes recorded "without animation" don't change over time, so this setting is not shown for them. To change the actual playback speed of the finished work, enter a "Playback Speed" value (default 1x, any value greater than 0 up to 10x, with up to 2 decimal places) either at the top of the "Stroke Playback" dialog or in the Properties panel on the right — both edit the same setting and actually affect playback, export, and the viewer (unlike the preview speed above). If you slow it down so much that the stroke wouldn't finish drawing before the object disappears, its display duration is extended automatically.
