--- title: "How to add an animated checklist with Claude (tested prompt and script)" description: "Three benefit lines slide in one after another on a dark card, and a green circle draws a white tick beside each. Install one skill and ask Claude Code, or run the Python script we tested yourself." url: https://www.recharm.com/effects/animated-checklist --- # How to add an animated checklist with Claude Three benefit lines slide in one after another on a dark card, and a green circle draws a white tick beside each. Made by the script on this page, from our own test clip. ## Get this effect 1. ### Switch to Code in your [Claude Desktop App](https://claude.com/download) 2. ### Install the skill (once) ``` Install the Recharm video effects skill: download https://recharm-growth-staging.s3.us-east-2.amazonaws.com/website/downloads/recharm-video-effects.zip and unzip it into ~/.claude/skills ``` 3. ### Ask for the effect ``` Add an animated checklist to input.mp4 Lines: Brighter in 7 days, Fragrance free, Dermatologist tested ``` ## Several videos, several effects, one ask Put your clips in the folder, mention them with @, and ask for everything at once. Claude runs one tested script after another on each clip, then joins them. Add an animated checklist to **@clip1.mp4**, put a sale badge on **@clip2.mp4**, give **@clip3.mp4** a VHS look, then join all three with crossfades. ## Settings you can change Ask Claude to change any of these, or edit them at the top of the script. | Setting | Default | What it does | | ------------ | ---------------------------------------------------------- | --------------------------------------------------------- | | `LINES` | `Brighter in 7 days, Fragrance free, Dermatologist tested` | The benefit lines, top to bottom. | | `START` | `0.5` | Second the first line slides in. | | `GAP` | `0.8` | Seconds between lines. | | `TICK_DELAY` | `0.25` | Seconds after its line starts that the tick draws itself. | | `GREEN` | `(34, 197, 94)` | Tick circle color. | | `Y` | `0.80` | Where the card's center sits (0 = top, 1 = bottom). | ## Without the skill Don’t want to install the skill? Paste this prompt into Claude Code and Claude writes the script itself. ``` Add an animated checklist to input.mp4: a dark (15, 15, 25) rounded card at 75% opacity, 84% of the frame width, centered horizontally with its center 80% of the way down, holding three lines in white bold text 31 px tall: "Brighter in 7 days", "Fragrance free" and "Dermatologist tested". The card fades in over 0.3 seconds at 0.5 seconds. The lines slide 43 px in from the left and fade up over 0.3 seconds, starting at 0.5, 1.3 and 2.1 seconds. To the left of each line, a green (34, 197, 94) circle 44 px across pops in 0.25 seconds after its line starts and a white tick draws itself inside it over 0.25 seconds. Everything stays on to the end. Use Python with Pillow to draw it and ffmpeg to put it on the video (don't rely on ffmpeg's drawtext filter), keep the audio, and save it as output.mp4. ``` ## Run it without Claude This is the exact script we tested. Save it as `animated-checklist.py` and run: ``` python3 animated-checklist.py input.mp4 output.mp4 ``` ``` #!/usr/bin/env python3 """Animated checklist: benefit lines slide in one by one on a dark card, each getting a green tick. Usage: python3 animated-checklist.py input.mp4 output.mp4 Needs ffmpeg and Pillow (pip install pillow). """ import json import math import subprocess import sys from pathlib import Path from PIL import Image, ImageDraw, ImageFont LINES = ["Brighter in 7 days", "Fragrance free", "Dermatologist tested"] START = 0.5 # second the first line slides in GAP = 0.8 # seconds between lines SLIDE = 0.3 # seconds each line takes to slide in TICK_DELAY = 0.25 # seconds after its line starts that the tick draws itself TICK = 0.25 # seconds the tick takes to draw SIZE = 0.058 # text height as a share of the frame width Y = 0.80 # where the card's center sits (0 = top, 1 = bottom) GREEN = (34, 197, 94) # tick circle color CARD = (15, 15, 25, 190) # card color and opacity FONTS = ["/System/Library/Fonts/Supplemental/Arial Bold.ttf", # macOS "/usr/share/fonts/truetype/dejavu/DejaVuSans-Bold.ttf", # Linux "C:/Windows/Fonts/arialbd.ttf"] # Windows FONT_FILE = next((f for f in FONTS if Path(f).exists()), None) or sys.exit("No bold font found: add one to FONTS") def ease_out(p): p = min(max(p, 0), 1) return 1 - (1 - p) ** 3 def tick(t, d): """A green circle with a white tick drawn stroke by stroke; d is the circle's width.""" img = Image.new("RGBA", (d, d)) pop = ease_out(t / 0.15) if pop <= 0: return img r = d / 2 * pop draw = ImageDraw.Draw(img) draw.ellipse([d / 2 - r, d / 2 - r, d / 2 + r, d / 2 + r], fill=GREEN) # the tick runs from a to b (short stroke) then b to c (long stroke) a, b, c = (d * 0.27, d * 0.52), (d * 0.43, d * 0.68), (d * 0.74, d * 0.35) p = ease_out(t / TICK) * 2 stroke = max(3, d // 9) if p > 0: k = min(p, 1) draw.line([a, (a[0] + (b[0] - a[0]) * k, a[1] + (b[1] - a[1]) * k)], fill="white", width=stroke, joint="curve") if p > 1: k = p - 1 draw.line([b, (b[0] + (c[0] - b[0]) * k, b[1] + (c[1] - b[1]) * k)], fill="white", width=stroke, joint="curve") return img def overlay(t): img = Image.new("RGBA", (w, h)) if t < START: return img font = ImageFont.truetype(FONT_FILE, round(w * SIZE)) row = round(w * SIZE * 2) d = round(w * SIZE * 1.4) pad = round(w * 0.05) card_w = round(w * 0.84) card_h = row * len(LINES) + pad x0, y0 = (w - card_w) // 2, round(h * Y - card_h / 2) fade = ease_out((t - START) / SLIDE) card = Image.new("RGBA", (w, h)) ImageDraw.Draw(card).rounded_rectangle([x0, y0, x0 + card_w, y0 + card_h], radius=round(w * 0.04), fill=CARD[:3] + (round(CARD[3] * fade),)) img.alpha_composite(card) for i, line in enumerate(LINES): t0 = START + i * GAP if t < t0: break p = ease_out((t - t0) / SLIDE) cy = y0 + pad // 2 + row * i + row // 2 shift = round((1 - p) * w * 0.08) layer = Image.new("RGBA", (w, h)) layer.alpha_composite(tick(t - t0 - TICK_DELAY, d), (x0 + pad, cy - d // 2)) ImageDraw.Draw(layer).text((x0 + pad + d + round(w * 0.04), cy), line, font=font, anchor="lm", fill="white") layer = layer.transform(layer.size, Image.AFFINE, (1, 0, shift, 0, 1, 0)) alpha = layer.getchannel("A").point(lambda v: round(v * p)) layer.putalpha(alpha) img.alpha_composite(layer) return img def probe(path): info = json.loads(subprocess.check_output(["ffprobe", "-v", "error", "-select_streams", "v:0", "-show_entries", "stream=width,height,r_frame_rate:format=duration", "-of", "json", path])) s = info["streams"][0] num, den = s["r_frame_rate"].split("/") return s["width"], s["height"], s["r_frame_rate"], float(num) / float(den), float(info["format"]["duration"]) def render(src, out): """Draw overlay(t) on every frame of src and save to out, keeping the audio.""" ff = subprocess.Popen(["ffmpeg", "-y", "-v", "error", "-i", src, "-f", "rawvideo", "-pix_fmt", "rgba", "-s", f"{w}x{h}", "-r", rate, "-i", "-", "-filter_complex", "[0:v][1:v]overlay=shortest=1,format=yuv420p[v]", "-map", "[v]", "-map", "0:a?", "-c:v", "libx264", "-crf", "18", "-c:a", "copy", out], stdin=subprocess.PIPE) for i in range(math.ceil(duration * fps)): ff.stdin.write(overlay(i / fps).tobytes()) ff.stdin.close() if ff.wait(): sys.exit("ffmpeg failed") src, out = sys.argv[1:3] w, h, rate, fps, duration = probe(src) render(src, out) ``` ## More captions and text - [AI chat reply animation **AI chat reply animation**](https://www.recharm.com/effects/ai-chat-typing) - [Animated bar chart **Animated bar chart**](https://www.recharm.com/effects/animated-bar-chart) - [Animated line graph **Animated line graph**](https://www.recharm.com/effects/animated-line-graph) - [Animated pie chart **Animated pie chart**](https://www.recharm.com/effects/animated-pie-chart) - [Animated underline **Animated underline**](https://www.recharm.com/effects/animated-underline) ## Find 3x _winning ads_ Recharm cuts your ad footage into tagged, searchable clips: hooks, testimonials, product shots. 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