How to Auto Generate Subtitles for Video: 4 Free Ways

How to Auto Generate Subtitles for Video: 4 Free Ways

You can auto generate subtitles for free with YouTube Studio, CapCut Web or Clipchamp. All three turn speech into text. The fourth way is to get an SRT file from one tool and reuse it everywhere else.

Featured Tool: Oh So Video (In-Browser Caption Generator)

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Oh So Video generates captions entirely in your browser. The page states the video never leaves your device, and in my test nothing asked for an account, a signup, or a payment at any step.

How to use it:

1. Open the page and drop in a video (MP4, MOV, WebM or MKV; the page allows up to 3 hours, 1 hour on a phone).
2. Leave Spoken language on Detect automatically, or pick your language from the 90+ list.
3. Wait for the transcript, fix any wrong words in the built-in editor, then export: .srt for YouTube and video editors, .vtt for web players, .mp4 with captions burned in, or .txt.

What I verified myself: I captioned an 18-second Vietnamese video, and auto-detect correctly picked Vietnamese. The first run downloads a speech model of about 340 MB (a few minutes, one time only); the 18-second clip itself was transcribed in under a minute. All exports downloaded fine, with no watermark and no paywall. The MP4 keeps your video's original size. It works for all video sizes, landscape, square, and vertical.

Way 1: YouTube Studio adds automatic captions after you upload

As of Oct 9, 2026, YouTube's automatic captions help page lists 67 supported languages for long videos and Shorts, including English, Spanish and Vietnamese. You do not need to turn anything on. If automatic captions are available, YouTube publishes them on the video once it finishes processing the audio.

YouTube says automatic captions can misrepresent what was said because of mispronunciation, accents, dialects or background noise, and creators should review them. To check and fix them:

1. Sign in to YouTube Studio and select Subtitles in the left menu.
2. Click the video you want to fix.
3. Under Subtitles, click the More icon next to the automatic captions.
4. Edit or remove any parts that were transcribed wrong.

Automatic captions may not be ready right after you upload, because processing time depends on how complex the audio is. For live streams, as of Oct 9, 2026, automatic captions are only available in English.

Way 2: CapCut Web creates auto captions inside its video editor

CapCut's AI caption generator page lays out three steps:

1. Open CapCut Web, click Media, then Upload to add your video to the timeline.
2. Click Captions in the left panel, choose Auto captions, pick the language spoken in the video, and click Generate.
3. Click Export in the top right corner, set the resolution and frame rate, then export.

The page says CapCut Web supports more than 20 languages and lets you change the font, size, color and position of the captions. You can also upload your own SRT file to replace the generated captions.

On cost, the FAQ says AI captions on CapCut Web are free to use with no hidden costs. But an illustration on the same page shows "2 uses/month" next to the Generate button. These two do not match, so check how many uses you have left in the tool before you caption a lot of videos.

Way 3: Clipchamp captions videos of any length and lets you download an SRT file

Microsoft Clipchamp has an automatic subtitle generator with four steps. Upload or record a video, choose the subtitle language, then adjust the font, colors, size and alignment. Finally, download your video along with the .SRT transcript file.

The Clipchamp FAQ makes three points. Auto captions are free for all Clipchamp users. There is no limit on the length of video you can caption. Clipchamp does not store your audio files.

Two limits to know: speech recognition handles one language at a time, and you can only download the transcript as .srt. The AI video editing page says automatic subtitles support over 80 languages and that Clipchamp works in Microsoft Edge and Google Chrome. There is also a Clipchamp app for Windows.

Way 4: make one SRT file and reuse it wherever you post

An SRT file is a text file with the spoken words and a timestamp for each line. With this file, you do not have to generate captions again for every platform. The tools above connect through it:

• Get the captions file from YouTube: YouTube's edit captions page tells you to click Edit next to the language, click Options, then Download subtitles. The page does not name the file format, so check the file extension before you move it to another tool.
• Get an SRT from Clipchamp: download it with your video in the last export step.
• Bring an SRT into CapCut Web: go to the captions section, choose to import captions, and upload the SRT file.
• Add an SRT to a video on Google Drive: the Drive help page accepts .srt, .sbv and many other formats. An .srt file must be plain UTF-8, and caption files must be smaller than 2 MB.

This works well when you post one video to several places. Fix a typo once in the SRT file, and every copy shows the same correct text.

Why doesn't your video have automatic captions?

YouTube lists six common reasons. The audio is still processing, the language is not supported, or the video is too long. The sound quality is poor, the video starts with a long silence, or several people talk over each other. The same issues also make captions less accurate in CapCut and Clipchamp, because every one of these tools relies on speech recognition.

Five common mistakes when you auto generate subtitles

Posting without reading them first. Names, product names and numbers are the words most often transcribed wrong. Read the whole thing before you post, especially for sales videos.

Letting two people talk over each other. Speech recognition will mix up their words. When you film, let each person finish a sentence before the other one speaks.

Mixing two languages in one section. Clipchamp says it only recognizes one language at a time. For a bilingual video, caption each part separately.

Saving the SRT file with the wrong encoding. Google Drive requires UTF-8. Open the file and save it again in a text editor with UTF-8 selected, so accented letters in languages like Spanish, French or Vietnamese stay correct.

Captions that are hard to read on a bright background. White text on a bright sky almost disappears. Add a dark text background or an outline. For more on text mistakes and on leaving room for buttons in vertical videos, browse the News section.

If you would rather skip making subtitles yourself, try Adam Proof Studio. Paste a product or article link and get a vertical video with voice-over, captions and music, sized for each platform.

Sources, accessed Oct 9, 2026:

• YouTube Help: Use automatic captioning and Edit or remove captions
• CapCut: AI caption generator
• Microsoft Clipchamp: Automatic subtitle generator and AI video editing
• Google Drive Help: Add captions to video files
• Illustrative photos: Unsplash (John Lockwood, Glenn Carstens-Peters), Unsplash License.

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