AI Subtitle Generator: Add Accurate Captions Without a Transcript
Most feed video is watched muted, which makes captions the difference between a clip that communicates and one that does not. The hard part is not the text, it is the timing.
Captions stopped being an accessibility afterthought the moment autoplay-without-sound became the default. A clip that relies on its audio is silent to most of the audience it reaches, and a clip with burned-in subtitles is not.
OpenFilmo transcribes the audio and times the captions to it, then lets you style and burn them in before export. Because it sits in the same workspace as voiceover and dubbing, a clip can be transcribed, translated and re-voiced without leaving the tab.
What it does
Built for this specific job, not a generic generator.
Automatic transcription
Speech is transcribed and timed to the audio, so you are not hand-placing cues against a waveform.
Burned in or exported separately
Bake subtitles into the video for social, or export them as a file for platforms that accept one.
Styled per channel
Set font, size, position and contrast once and reuse it, so a channel looks consistent.
Pairs with dubbing
Transcribe, translate and re-voice in one workspace using the same credit balance.
How it works
Four steps, no timeline to learn.
Upload the clip
Any generated or uploaded video. Clearer audio produces a cleaner transcript — fix loudness before transcribing if the track is poor.
Generate the transcript
Speech is transcribed and timed automatically. Skim it for proper nouns and product names, which are the most common errors.
Style and position
Choose font, size and placement. Keep subtitles out of the platform UI zone at the bottom of vertical video.
Burn in and export
Bake captions in for social placements, or export a subtitle file alongside the video where the platform accepts one.
What people make with it
The jobs this actually gets used for.
Short-form social
Burned-in captions for Reels, TikTok and Shorts, where most viewing is muted.
Explainer and product walkthroughs
Captions that carry the argument when the sound is off.
Multi-language versions
Transcribe once, translate, then re-voice for another market in the same workspace.
Accessibility and compliance
Captions for audiences and contexts where they are required rather than optional.
Why captions decide reach
A clip that needs its audio is invisible to most of the feed.
Autoplay defaults to muted on the platforms where short video is watched. That single behaviour turns captions from a nicety into the primary channel for the message — and it is why two otherwise identical clips can perform very differently.
Timing is the part that is genuinely difficult to do by hand, and it is where automatic transcription pays for itself. What still needs a human pass is vocabulary: product names, proper nouns and technical terms are the errors that survive every pipeline.
Consistency matters more than styling cleverness. One legible style reused across every upload makes a channel recognisable and removes a decision from every single export.
Credits and plans
Generation is metered in credits, shared across every tool.
A five-second video costs 5 credits and one image costs 2. The Free plan gives you 30 credits every month with no credit card, no watermark and commercial use included. Paid plans start at $9 for 400 credits and add faster generation, parallel tasks and higher export resolution.
Related guides
Longer reads on the same workflow, from the OpenFilmo blog.
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AI tools
Single-purpose tools that run in the same workspace, on the same credit balance.
Related workflows
Closely related tools and guides on the same problem.
Frequently asked questions
How accurate is the transcription?
Good on clear audio, weaker on noisy tracks and heavy accents. Always skim for proper nouns, product names and technical terms, which are the errors most likely to survive.
Can I burn subtitles into the video?
Yes. Bake them in for social placements, or export a subtitle file separately where the platform accepts one.
Can I style the captions?
Yes — font, size, colour and position. Set it once and reuse it so a channel stays consistent.
Does it work with dubbing?
Yes. Transcribe, translate and re-voice in the same workspace, all against one credit balance.
What languages are supported?
Captions and dubbing cover many languages. Generate the transcript in the source language first, then translate for each target market.
Where should I place subtitles on vertical video?
Above the platform UI zone at the bottom of the frame, where captions are most likely to be covered by interface elements and captions of the platform itself.
How much does it cost?
Caption generation draws from the same credit balance as generation and audio work. The Free plan gives 30 credits per month with no credit card.
Can I export a subtitle file?
Yes, alongside the video, for platforms and players that accept a separate subtitle track rather than burned-in text.
Video prompt collections
Copy-ready prompt sets for text-to-video, image-to-video, product, UGC, social and tutorial clips.