🎬 Add Subtitles to Videos

Turn a talking video into a captioned MP4 with word highlighting.

The input is the video. Upload a file or paste a direct URL, pick a font and colors, and download the subtitled clip plus an SRT and a word-level transcript. Each video can be at most 3 minutes and 50 MB.

A transcript JSON file is optional. Most runs only need the video — speech is transcribed automatically. If you already have a transcript (for example you fixed a few words in a previous output), attach that file and it replaces automatic transcription. Captions are burned from your JSON instead.

💡 Perfect for

• 📣 Influencers and creators: Caption TikToks, Reels, and Shorts so the hook still lands on mute.
• 🎥 UGC content: Subtitle product demos, testimonials, and creator ads before they go to brands or ad accounts.
• 🛍️ Ecommerce and brands: Caption unboxings, how-tos, and shoppable clips for paid social.
• 🧑‍💼 Agencies: Caption client videos through the Apify API instead of editing by hand.
• 🎙️ Podcasts and YouTube: Burn captions onto clips, trailers, and audiograms.
• 🎓 Courses and explainers: Make lessons readable without the sound on.
• 🤖 Avatar and talking-head videos: Overlay karaoke-style subtitles on generated spokespeople.
• 🔗 Automations: Call the Actor from Make, Zapier, n8n, or the Apify API.

✨ What you get

For the input video the Actor:

1. Gets word-level captions — either by transcribing the audio, or by using your optional transcript file.
2. Burns captions into the video, highlighting the word being spoken.
3. Saves a captioned MP4, an SRT, a JSON transcript, and a dataset row with download links.

The output keeps the source frame rate. Clips larger than 1080p on the long side are scaled down so rendering stays fast. Captions are drawn on top.

📄 Optional transcript file

Leave transcriptJson empty unless you want to control the wording.

Input	What happens
Video only	Audio is transcribed, then captions are burned in.
Video + transcript JSON	Transcription is skipped. Your JSON is burned in as captions.

Use the transcript file when you want to perfect the output: download transcript-1.json from a previous result, change only the wrong word values, and pass that file with the same video. Leave start and end unchanged so highlighting still matches the audio. Segment text is rebuilt from the words.

{
  "language": "en",
  "text": "Hello world this is a demo",
  "segments": [
    {
      "text": "Hello world",
      "start": 0.2,
      "end": 1.1,
      "words": [
        { "word": "Hello", "start": 0.2, "end": 0.5 },
        { "word": "world", "start": 0.55, "end": 1.1 }
      ]
    }
  ]
}

You can upload the file in transcriptJson, or paste the same JSON into transcriptJsonContent.

🔤 Font family

Choose one of these 20 typefaces with fontFamily:

Value	Preview
montserrat
poppins
oswald
inter
roboto
rubik
nunito
anton
bebas_neue
archivo_black
raleway
lato
work_sans
dm_sans
outfit
kanit
teko
russo_one
righteous
barlow_condensed

🎨 Colors

textColor, highlightColor, and outlineColor accept:

• Hex: #FFF or #FFFFFF
• Names: white, black, red, orange, yellow, green, blue, purple, pink, cyan, magenta, gray, navy, teal, gold, brown, and similar CSS color names

highlightColor is the background overlay on the word currently being spoken.

🚀 How to use

1. Add a video to video — upload a file or paste a direct URL.
2. Optionally add a transcript JSON if you want to skip transcription and use your own wording.
3. Set font family, size, and colors.
4. Start the Actor and download subtitled-video-1.mp4 from the key-value store.

One video per run, at most 3 minutes and 50 MB. Start another run for each extra clip.

📥 Input example

{
  "video": "https://api.apify.com/v2/key-value-stores/3ZzUVcATxmN3HCTaI/records/qa-speech.mp4",
  "fontFamily": "montserrat",
  "fontSize": 40,
  "textColor": "white",
  "highlightColor": "#FFCC00",
  "outlineColor": "black",
  "uppercase": true,
  "position": "bottom",
  "maxWordsPerCaption": 4,
  "language": "en"
}

With an optional transcript file:

{
  "video": "https://api.apify.com/v2/key-value-stores/3ZzUVcATxmN3HCTaI/records/qa-speech.mp4",
  "transcriptJson": "https://api.apify.com/v2/key-value-stores/.../records/transcript-1.json",
  "fontFamily": "montserrat",
  "highlightColor": "#FFCC00"
}

📤 Output example

{
  "source_video": "https://api.apify.com/v2/key-value-stores/3ZzUVcATxmN3HCTaI/records/qa-speech.mp4",
  "subtitled_video_url": "https://api.apify.com/v2/key-value-stores/.../records/subtitled-video-1.mp4",
  "srt_url": "https://api.apify.com/v2/key-value-stores/.../records/subtitles-1.srt",
  "transcript_url": "https://api.apify.com/v2/key-value-stores/.../records/transcript-1.json",
  "transcript_text": "Hello world this is a demo",
  "language": "en",
  "duration_seconds": 12.4,
  "word_count": 6,
  "font_family": "Montserrat",
  "font_size": 40,
  "highlight_color": "#FFCC00",
  "used_transcript_json": false
}

The first captioned file is also stored as subtitled-video-1.mp4 in the default key-value store.

⚙️ Parameters

Parameter	Type	Required	Description
video	file or URL	Yes	Video to caption. Upload a file or paste a direct link. One per run, 3 minutes and 50 MB max.
transcriptJson	JSON file or URL	No	Optional transcript file. When set, replaces automatic transcription.
transcriptJsonContent	JSON object	No	Optional. Paste the same transcript JSON in the console.
fontFamily	string	No	Caption typeface. One of the 20 fonts listed above.
fontSize	integer	No	Caption size in pixels (16–120). Default 40.
textColor	hex or name	No	Color of idle words. Default white.
highlightColor	hex or name	No	Overlay color for the spoken word. Default #003399.
outlineColor	hex or name	No	Caption stroke color. Default black.
uppercase	boolean	No	Force uppercase captions. Default true.
position	string	No	bottom, center, or top.
maxWordsPerCaption	integer	No	Words shown together on screen. Default 5.
language	string	No	Spoken language for transcription. Default en.
mistralApiKey	secret	No	Optional Mistral key override.