# AI subtitle generator for automatic video captions

Generate timed captions from the speech in your video. SubLunio supports 100 speech recognition languages and 118 subtitle output options. Preview the result, then export original, translated or bilingual subtitles in SRT, VTT or ASS after full generation.

## Choose your video and dialogue track

Select a local video in the workspace above. SubLunio extracts audio on your device and uploads only the extracted audio for processing; your original video stays on your device. If the file contains an original soundtrack, a dub and a commentary track, choose the dialogue you actually want to caption before generating.

The browser reads files in chunks, so videos larger than 2 GB can be processed without loading the whole file into memory. Available local space, audio decoding support and account duration limits still apply. Keep the tab open during extraction and upload; use the desktop queue when processing several videos.

## Choose original captions or translated subtitles

The source language is the language spoken in the selected audio track. Leave it on Auto to detect the speech, or select the known language. The target language is the text you want to read. For English captions on an English video, choose English for both settings. After full generation, the original-only download also gives you the recognized source text.

To read the video in another language, choose a different subtitle target. For example, Japanese speech can be transcribed and translated into English subtitles. The target menu has 118 output options, including separate Simplified and Traditional Chinese choices. Changing the website interface language does not select your subtitle target.

[Browse all subtitle translation languages](https://sublunio.com/subtitle-translator#all-languages)

## Supported speech recognition languages

SubLunio offers 100 source languages for speech recognition. The list below describes audio the generator can recognize; subtitle translation uses a separate output list. Auto detects the source and does not count as another language. Chinese is a source option, while Simplified and Traditional Chinese are separate subtitle output choices.

Check this list when deciding whether your recording is supported. If Auto identifies the wrong language, select the known source language before processing. A supported option does not guarantee the same accuracy for every recording: accents, overlapping speakers, background music and mixed-language dialogue can affect the result. Preview speech that represents the recording you need to caption.

- English (en)

- Chinese / 中文 (zh)

- Cantonese / 粵語 (yue)

- German / Deutsch (de)

- Spanish / Español (es)

- Russian / Русский (ru)

- Korean / 한국어 (ko)

- French / Français (fr)

- Japanese / 日本語 (ja)

- Portuguese / Português (pt)

- Turkish / Türkçe (tr)

- Polish / Polski (pl)

- Catalan / Català (ca)

- Dutch / Nederlands (nl)

- Arabic / العربية (ar)

- Swedish / Svenska (sv)

- Italian / Italiano (it)

- Indonesian / Bahasa Indonesia (id)

- Hindi / हिन्दी (hi)

- Finnish / Suomi (fi)

- Vietnamese / Tiếng Việt (vi)

- Hebrew / עברית (he)

- Ukrainian / Українська (uk)

- Greek / Ελληνικά (el)

- Malay / Bahasa Melayu (ms)

- Czech / Čeština (cs)

- Romanian / Română (ro)

- Danish / Dansk (da)

- Hungarian / Magyar (hu)

- Tamil / தமிழ் (ta)

- Norwegian / Norsk (no)

- Thai / ไทย (th)

- Urdu / اردو (ur)

- Croatian / Hrvatski (hr)

- Bulgarian / Български (bg)

- Lithuanian / Lietuvių (lt)

- Latin / Latina (la)

- Māori (mi)

- Malayalam / മലയാളം (ml)

- Welsh / Cymraeg (cy)

- Slovak / Slovenčina (sk)

- Telugu / తెలుగు (te)

- Persian / فارسی (fa)

- Latvian / Latviešu (lv)

- Bengali / বাংলা (bn)

- Serbian / Српски (sr)

- Azerbaijani / Azərbaycanca (az)

- Slovenian / Slovenščina (sl)

- Kannada / ಕನ್ನಡ (kn)

- Estonian / Eesti (et)

- Macedonian / Македонски (mk)

- Breton / Brezhoneg (br)

- Basque / Euskara (eu)

- Icelandic / Íslenska (is)

- Armenian / Հայերեն (hy)

- Nepali / नेपाली (ne)

- Mongolian / Монгол (mn)

- Bosnian / Bosanski (bs)

- Kazakh / Қазақша (kk)

- Albanian / Shqip (sq)

- Swahili / Kiswahili (sw)

- Galician / Galego (gl)

- Marathi / मराठी (mr)

- Punjabi / ਪੰਜਾਬੀ (pa)

- Sinhala / සිංහල (si)

- Khmer / ខ្មែរ (km)

- Shona / ChiShona (sn)

- Yoruba / Yorùbá (yo)

- Somali / Soomaali (so)

- Afrikaans (af)

- Occitan (oc)

- Georgian / ქართული (ka)

- Belarusian / Беларуская (be)

- Tajik / Тоҷикӣ (tg)

- Sindhi / سنڌي (sd)

- Gujarati / ગુજરાતી (gu)

- Amharic / አማርኛ (am)

- Yiddish / ייִדיש (yi)

- Lao / ລາວ (lo)

- Uzbek / Oʻzbek (uz)

- Faroese / Føroyskt (fo)

- Haitian Creole / Kreyòl ayisyen (ht)

- Pashto / پښتو (ps)

- Turkmen / Türkmençe (tk)

- Norwegian Nynorsk / Nynorsk (nn)

- Maltese / Malti (mt)

- Sanskrit / संस्कृतम् (sa)

- Luxembourgish / Lëtzebuergesch (lb)

- Burmese / မြန်မာ (my)

- Tibetan / བོད་སྐད་ (bo)

- Filipino (Tagalog) / Filipino (tl)

- Malagasy (mg)

- Assamese / অসমীয়া (as)

- Tatar / Татарча (tt)

- Hawaiian / ʻŌlelo Hawaiʻi (haw)

- Lingala / Lingála (ln)

- Hausa (ha)

- Bashkir / Башҡортса (ba)

- Javanese / Basa Jawa (jw)

- Sundanese / Basa Sunda (su)

## Check the free subtitle preview

You can start a web preview as a guest, without registering. The preview covers a continuous window of up to 5 minutes beginning at the first subtitle, limited by the remaining video duration. A silent opening therefore does not have to occupy the preview. Watch the selected soundtrack and check how the generated lines follow the dialogue.

Review a clear sentence and a difficult passage. Names, technical terms and fast speaker changes are useful checks. Enter a focused glossary before generating if recurring terms need preferred wording. When translating, bilingual display helps you compare the recognized original with the translation and identify which stage needs correction.

## Continue full generation from the same task

When the preview is useful, sign in to save the task and continue with the rest of the video. Eligible guest work can be attached to your account in the same browser. The existing uploaded audio and completed preview are reused. Keep the guest recovery information so you can return to the task if needed.

Full subtitles cost USD $1 per hour of the entire video, rounded up to a cent. Preview minutes are included in that total and are not deducted from the billable duration. Pay for the task or use account credit. Card payments start at USD $1.00; any amount above the task price remains as reusable credit.

## Download SRT, VTT or ASS captions

A completed task offers original, translated and bilingual subtitle downloads. Use SRT for a broadly compatible local player, VTT for a web player that requires WebVTT, or ASS for styled subtitles in a compatible application. These are separate subtitle files, so generating captions leaves the original video unchanged.

Test the download with the exact video edition you plan to watch or share. Check timing, character display and important names in the final player. Signed-in users retain subtitle records, while uploaded audio is temporary under the retention policy. Local preview playback still depends on the media being available on your device.

## Review automatic captions before sharing

Automatic generation reduces the work of transcription and timing, but unclear audio can still produce incorrect words. Listen again to important statements, specialist vocabulary and names before publishing. You can edit the downloaded subtitle file in your preferred subtitle editor. If a task fails, check its existing status before starting another task so you can investigate the same job.

## How do I automatically add same-language captions to a video?

Choose your video and dialogue track, then select the same source and target language, such as English for both. Check the preview and continue full generation to download timed subtitles. You can also select the original-only download from a completed task.

## How many spoken languages can SubLunio recognize?

SubLunio has 100 speech recognition languages. This source list is separate from the 118 subtitle output options. Auto detects the spoken language and is not an additional language.

## Can I try the AI subtitle generator without an account?

Yes. Guests can generate a free web preview of up to 5 minutes, starting at the first subtitle. Sign in to save the task and continue full processing.

## Does automatic subtitle generation upload my video?

The video stays on your device. SubLunio extracts audio locally and uploads the extracted audio for speech recognition and subtitle generation.

## Which subtitle files can the automatic generator export?

After full generation, download SRT, VTT or ASS in original, translated or bilingual versions. Review the file with the matching video in your intended player.

## Keep exploring

- [Translate subtitles into 110+ languages](https://sublunio.com/subtitle-translator)

- [Display original and translated subtitles](https://sublunio.com/bilingual-subtitles)

- [Choose the correct audio track](https://sublunio.com/guides/video-audio-tracks)

- [Generate subtitles for multiple videos](https://sublunio.com/batch-subtitle-generator)

Source page: https://sublunio.com/auto-subtitle-generator

Last updated: 2026-10-08