Free AI Subtitle Generator Online
100% automatic and Free
Auto-generate subtitles and captions for any video. Powered by Floyo using Whisper TTS model.
How to add subtitles to your video
Three steps, about a minute, nothing to install.
Upload your video
Drag and drop your file or choose one. MP4 and MOV up to 100 MB and 5 minutes.
Pick language & style
Select the language spoken in the clip and style the captions — font, size, colour and position — with a live preview. Transcription runs on an open-source Whisper workflow on Floyo.
Download
Generate and download your video as an MP4 with the captions burned in.
Accurate AI subtitles, burned right into your video
Everything you need to caption and style your clips.
Auto-generate with AI
An open-source Whisper workflow handles speech recognition — accents, background noise and fast speech — with no manual transcription.
Built-in language support
Captions render cleanly for Latin, Cyrillic, Greek, Vietnamese and Chinese scripts, and the right font is chosen automatically for the language you pick.
Customise the style
Set the font, size, colour and position, and preview exactly how the captions will sit before you render.
Burned-in MP4 output
Download a ready-to-post MP4 with hardcoded captions — no extra software and no separate file to manage.
Who uses this subtitle generator?
Creators, teams and developers — here's how.
Content creators
Caption YouTube videos, TikToks and Reels. Most people watch with sound off — subtitles keep them watching.
Marketers & agencies
Subtitle ads, product demos and webinar recordings so they land in any feed.
Educators & course creators
Make lectures and tutorials accessible and easier for non-native speakers to follow.
Developers & teams
Use the Floyo API to build subtitle generation into your own product and run ComfyUI workflows programmatically.
How does an AI subtitle generator work?
An AI subtitle generator uses speech recognition to turn the spoken words in a video into text. First, the audio track is extracted from the video. Then an AI model analyses the audio and maps it to text, detecting word boundaries and pauses. Finally, the text is split into timed segments and burned into the video frames. Modern models like Whisper support many languages and handle accents and background noise well.
What is Floyo?
Floyo is the only platform with team collaboration for ComfyUI in the browser. You run open-source AI workflows with no install, share run history, assets and models across your team, and pay only when you generate. This tool runs a ComfyUI workflow on Floyo that chains audio extraction, Whisper transcription and video rendering. Try it at floyo.ai.
Frequently asked questions
Is this subtitle generator really free?
Yes. There is no login, no credit card and no watermark on your exported video. It is a demo of what the Floyo API can do.
What video formats and sizes are supported?
MP4 and MOV files up to 100 MB and about 5 minutes long. Trim or compress longer or larger files first.
How accurate are the subtitles?
It depends on audio quality, but the Whisper model typically achieves high accuracy on clear speech.
Which languages can it caption?
Whisper transcribes many spoken languages. Burned-in captions render cleanly for Latin, Cyrillic, Greek, Vietnamese and Chinese scripts, and the right font is selected automatically for the language you choose.
How long can the video be?
Up to about 5 minutes. The captioning workflow loads every frame into memory, so longer clips can exhaust GPU memory and fail.
Can I customise the subtitle style?
Yes. Change the font, size, colour and position, and see a live preview before you render.
What is Floyo?
Floyo is the only platform with team collaboration for ComfyUI in the browser. You run open-source AI workflows with no install, share run history, assets and models across your team, and pay only when you generate. Try it at floyo.ai.
What is ComfyUI?
ComfyUI is an open-source visual workflow engine for AI. You connect nodes to build pipelines that transcribe audio, generate images or edit video. Floyo runs ComfyUI in the browser. Browse workflows.
What is the Floyo API?
The Floyo API lets you run any ComfyUI workflow programmatically — one endpoint, no GPU setup, pay only when you generate. This subtitle tool is one example built on it. Read the API docs.
Run open-source AI workflows in the browser
Floyo is the only platform with team collaboration for ComfyUI. No install. Shared run history, assets and models. Pay only when you generate.