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Auto Subtitle Generator

Accurate AI subtitles, generated online from one typed request — so your video makes sense with the sound off.

Valmera's auto subtitle generator turns your video's speech into accurately timed, readable subtitles in one chat request. The AI agent transcribes every word, you correct anything it misheard in an editable transcript, and the subtitles are burned into a full-quality export — watchable on mute, in any feed, by every viewer, on every platform.

Subtitle Your Video Free

Upload, type "add subtitles", verify, export. No credit card required.

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How to Generate Subtitles Automatically

  1. 1
    Upload your video
    Create a free account at valmera.io and upload your video — up to 2GB or 3 hours. Valmera runs a one-time analysis with visible progress and produces a word-level transcript of everything said on camera.
  2. 2
    Type the subtitle request
    Type "add subtitles" — or be specific about readability: "subtitle this so it can be watched on mute" or "clean white subtitles at the bottom, five words at a time". The agent generates and times every line from the transcript.
  3. 3
    Verify, then export
    Skim the editable transcript, fix any misheard word (the subtitles re-render from your correction), and export. The finished H.264 MP4 renders from your original upload at source quality with the subtitles burned in.

The one-time analysis of a long video takes a while and shows visible progress. Subtitle changes after that are single chat messages.

Subtitles for Viewers Watching Without Sound

A large share of any video's audience never turns the sound on. Feeds autoplay muted; people watch in open offices, on trains, in bed next to someone sleeping; deaf and hard-of-hearing viewers rely on text entirely; and viewers working in a second language follow written words more comfortably than fast speech. Subtitles are how your video keeps all of those people instead of losing them at second one.

Because Valmera burns the subtitles into the frame, there's no "turn on CC" step and no platform-by-platform subtitle upload — the words are simply there, identical on TikTok, YouTube, LinkedIn, or a file shared over email. One video, readable everywhere.

Accuracy You Can Verify, Not Just Trust

Automatic transcription is good, and it is not infallible — names, jargon, and crosstalk trip every engine. Valmera's answer isn't a decorative accuracy percentage; it's a workflow you can check. The word-level transcript sits next to the player: read it, click into any line, fix a word, and the subtitles re-render from the corrected text with timing preserved.

The same honesty runs through the agent itself: Valmera's honesty layer verifies every reply against the edit actually performed, so the agent can't claim your subtitles were added or fixed unless they really were. On language support, the transcript language is auto-detected from the audio — English is the best-tested path today, and for other languages the editable transcript is your verification step before export.

Readable by Design

Readability is mostly three decisions, and each is a sentence in chat. Line length: anywhere from 1 to 16 words per subtitle — shorter lines for pace, longer for lecture-style footage. Size and position: S to XL on a continuous scale, placed at the bottom, middle, or top so subtitles never fight your framing or a platform's UI overlays. Contrast: any text color, chosen against your footage — plain high-contrast white is the accessibility workhorse for a reason.

When you want presentation on top of readability — animated entrances, per-word emphasis, styled presets — the same transcript powers the full caption system, including karaoke word-by-word highlighting. Every option is documented in the captions docs.

Who Needs an Auto Subtitle Generator

Educators subtitling lessons so students can study anywhere. Teams publishing product walkthroughs that get watched at desks with the sound off. Marketers whose ads autoplay muted in feeds. Creators who want every upload accessible by default rather than as an afterthought. And anyone posting to an audience that spans languages and listening environments — which, on the open internet, is everyone.

Make Your Video Readable

Accurate subtitles, verified by you, burned in for every platform. Free to try.

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More Than a Subtitle Generator

Subtitles are one request inside a full agentic editor. The same conversation can cut silences, drop filler words, add titles and lower thirds, mix in music that ducks under speech, and reframe for vertical — each described in plain English, each verified by the honesty layer. Explore all the AI video editing tools or see plans and pricing.

Frequently Asked Questions

Use a browser tool that does the work from a request instead of a timeline. In Valmera you upload the video (up to 2GB or 3 hours), type "add subtitles", check the preview, and export — the AI agent transcribes the speech, times each subtitle to the spoken word, and burns the result into a full-quality MP4. Nothing to install, and no subtitle track to configure on the platform you post to.
Valmera transcribes at the word level and times subtitles to the actual audio, which is very reliable on clear speech. It won't be perfect on every proper noun or mumbled aside — no automatic transcriber is — so instead of promising a fake accuracy percentage, Valmera gives you an editable transcript: fix any word and the subtitles re-render from the corrected text. You verify the words once, not the timing.
The transcript language is auto-detected from your audio rather than picked from a menu, and English is the best-tested path today. If your footage is in another language, try it and check the preview against the editable transcript before exporting — the honest answer is that quality varies by language, and we'd rather you verify than be promised a number.
No. Valmera burns subtitles into the video itself — there is no SRT or VTT import or export. That guarantees the subtitles appear for every viewer on every platform with zero setup, but it also means there's no separate sidecar file. If a platform or client specifically requires an SRT deliverable, generate that file with a dedicated subtitle tool; if the goal is a video everyone can follow, burned-in does the job.
Yes, because much of your audience never hears that audio. Social feeds commonly autoplay muted, plenty of people watch in offices, transit, or beside a sleeping child, and deaf and hard-of-hearing viewers depend on text outright. Subtitles also help viewers watching in a second language and anyone who rewinds because a line was fast. Good audio serves the viewers who listen; subtitles serve everyone.
Yes — Valmera's Free plan includes 20 credits every day (they reset daily and don't accumulate) plus a one-time 150-credit welcome bonus, no credit card required. Each request charges credits in proportion to the AI work actually done, and a subtitle pass sits at the cheap end. Plus is $20/mo for 800 credits per billing cycle; Pro is $50/mo for 2,400.
In everyday use the words blur together; the useful distinction is intent. Subtitles carry the spoken words as readable text — the focus of this page. Caption styling is about presentation: presets, fonts, animations, per-word emphasis. Valmera does both from the same transcript, so start here for readability and move to the add-captions tool when you want the styled, short-form look.

Generate Accurate Subtitles

Auto-transcribed, human-verified, burned into a source-quality export. Free plan — no credit card required.

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Related Articles

Add Captions to Video
The styled side of the same system — 11 presets, 12 fonts, per-word emphasis.
Karaoke Captions
Word-by-word highlight captions in the TikTok style — up to 6 words per line.
Captions Documentation
Every subtitle and caption option — sizes, positions, colors, animations.
All AI Video Editing Tools
Cut, caption, mix, and finish video — each tool is one typed request.