AI Auto Subtitle Generator
Upload a video and let AI transcribe the speech and add accurate, well-timed subtitles and captions — short, readable lines synced to every word. Free to try.
What is an auto subtitle generator?
An auto subtitle generator is a free online tool that listens to your video, transcribes the spoken audio with AI, and turns it into accurate, time-synced subtitle lines burned in or exported as captions — no manual typing or timing. Upload your clip, add an optional language or style note, and Agent P writes and syncs the captions for you.
Instead of pausing every few seconds to type and nudge timecodes, the AI splits speech into short, readable lines and locks each one to the exact moment it is spoken. You review, tweak wording or timing, then burn the subtitles into the frame or export them.
Use it to add subtitles to a video for YouTube, TikTok, Reels, courses, webinars or ads — then pass the same clip to the AI video editor for final trims, or send it to the AI video translator to caption it in another language.
Auto-generated subtitles appear as short, readable caption lines pinned to the bottom of the frame, each timed to the exact words being spoken. Below are sample caption previews — free AI-generated frames with subtitle lines burned in the way your own clips would look.
AUTO-CC00:01:12,480
EN · 2 lines
AUTO-CC00:00:27,900
EN · 1 line
To auto-generate subtitles, upload your video, and the AI transcribes the audio, splits it into short caption lines, syncs each line to the speech, and lets you review and export — usually in minutes. Nothing to install; the transcript rail does the timing for you.
The subtitle transcript is a list of time-coded cues — each with a start and end timecode and a short caption line — the same structure as an SRT or VTT file. Here is what a few cues from a captioned clip look like on the transcript rail.
What videos should you auto-caption?
Talking-head videos, tutorials, interviews, podcasts, courses, webinars and social clips caption best — anything with clear spoken audio.
- Social & Shorts. Most viewers watch muted, so on-screen captions lift retention.
- Tutorials & courses. Reinforce steps and make lessons searchable.
- Podcasts & interviews. Turn long talk into readable, clippable captions.
- Ads & explainers. Land the message even with the sound off.
Repurposing a still or a script into a clip first? Start in the AI video generator or turn a photo into motion with the image to video generator, then caption it here.
AI captioning transcribes and time-syncs an entire video in minutes with word-level timing, while manual captioning means typing every line and nudging each timecode by hand — slower and easy to drift out of sync.
- No manual timing. Every line is anchored to the audio automatically.
- Clean line breaks. Long sentences split into short, readable captions.
- Consistent style. One look and position across the whole clip.
- Review before export. You keep control of wording, spelling and timing.
Pixazo's auto subtitle generator transcribes your video, times each caption, splits long lines, lets you edit the wording, styles the subtitles, and burns them in or exports them.
| Feature | What it does |
|---|---|
| AI transcription | Listens to the audio and writes out the spoken words. |
| Word-timed sync | Locks each caption line to the moment it is spoken. |
| Smart line splitting | Breaks long speech into short, readable caption lines. |
| Editable transcript | Fix wording, spelling or timing before you export. |
| Caption styling | Set the look and position so subtitles stay legible. |
| Burn in or export | Bake captions into the frame or take the subtitle file. |
The auto subtitle generator accepts MP4, MOV or WEBM videos up to 50MB and returns a time-synced transcript you can edit, burn in or export, free to start in any modern browser. AI captioning is fast, but clear audio matters — here is the honest read.
- Input formatsMP4 / MOV / WEBM · 50MB
- OutputTime-synced captions
- TimingWord-level sync
- Language noteOptional, in the box
- EditingReview before export
- DevicesDesktop & mobile
- Pricing tierFree to start
- Accuracy depends on clear audio — heavy noise or crosstalk can cause errors.
- Strong accents, jargon and proper names may need a quick manual fix.
- Very long or large files should be trimmed to stay under the size limit.
- Overlapping speakers can blur who said what without a review pass.
- Captions are AI-generated, so proofread before you publish.
This tool auto-transcribes and times captions from your video's audio; it is not a manual re-writer and it works best when the speech is clear. Here is an honest read on what it will not do, so you know what to expect before you upload.
- It can't invent missing audio. If a section has no clear speech, there is nothing to caption — add narration first with the AI voiceover generator.
- It won't rewrite your script. It captions what is said; it does not paraphrase or clean up filler unless you edit it.
- It's not a translator by default. It captions in the spoken language — for another language use the AI video translator.
- Very noisy audio may drift. Loud backgrounds or overlapping voices can reduce accuracy.
- You sign up for a free Pixazo account to use it; higher volume needs a paid plan.
Is the auto subtitle generator free to use?
Yes, it is free to start. You can upload a video and auto-generate subtitles free with a credit card. Higher volume and extra features come with Pixazo's paid plans, but you do not need a plan to try the tool.
What video formats can I upload?
You can upload an MP4, MOV or WEBM video up to 50MB. Clear spoken audio gives the most accurate captions, so a clean recording works best.
How accurate are the subtitles?
Accuracy is high when the audio is clear. Strong accents, background noise, jargon or overlapping speakers can introduce errors, so review the transcript and fix anything before you export.
Can I edit the captions and timing?
Yes. The transcript is fully editable — you can correct wording, adjust line breaks and nudge timing in Agent P before you burn in or export the subtitles.
Can I export an SRT or VTT file?
The output is a time-synced transcript you can burn into the video or take as a subtitle file. Ask for the format you need in the language or style note, or export it from Agent P.
Can it caption in another language?
It captions in the language spoken in the video. To caption or dub into a different language, run the clip through the AI video translator after generating the subtitles.
How long does it take?
Usually minutes, depending on the length of the clip. Upload your video, open Agent P, and the synced captions are ready to review shortly after.
Do you store my uploaded video?
Your video is used to create the captions. For details on how long data is kept and how it is handled, see Pixazo's privacy policy.
Deepak Joshi
Deepak Joshi is a Content Marketing specialist having a combined experience of 10+ years working in the digital world. He is one of the active contributors to Pixazo Blog. He also covers Pixazo's video toolkit, from this auto subtitle generator to the AI video editor and the HD video converter.
Auto-caption your video now
Upload a clip and let AI transcribe and time your subtitles — accurate, readable captions synced to every word, free to start.