How to Add Subtitles to Videos

This guide shows you how to add subtitles and closed captions to video content for accessibility and improved learning outcomes. Use this process when creating courses for sound-sensitive environments or to support learners who benefit from text alongside audio.

Before You Start

• Access to your video platform or course authoring tool with caption/subtitle functionality

• A video file ready for captioning (MP4, WebM, or other supported format)

• Either a transcript of the video content, an SRT or VTT caption file with timings, or access to AI caption generation tools

• Knowledge of the language(s) you want to caption (or AI transcription enabled)

• Optional: A text editor (Notepad, VS Code) if manually creating SRT/VTT files

Steps

1. Choose your caption method — Decide whether to upload a pre-made caption file (SRT or VTT format with timing information), use AI-powered auto-sync to generate captions from audio, or type captions manually. Auto-sync is fastest for most videos under one hour with clear audio quality.

2. Prepare or generate caption content — If uploading a file, ensure your SRT or VTT file includes timestamps for when each line appears and disappears. If using auto-sync, have a full transcript ready to paste. If typing manually, have your script on hand to reference while watching the video.

3. Access the caption editor in your platform — Navigate to your video's settings or details page and locate the Subtitles or Captions section. Click the option to add a new language and select your target language from the dropdown menu.

4. Upload or import your caption file — If using a pre-made file, select the Upload option and choose your SRT or VTT file. Confirm you're uploading with timing information so captions sync automatically. If using auto-sync, paste your transcript and let the system synchronize it to the video audio.

5. Review and edit captions for accuracy — Play through the video and verify that captions appear at the correct moments and match what is actually said. Use the built-in editor to correct any transcription errors, add descriptions for non-dialogue audio (e.g., [applause], [thunder]), and ensure deaf or hard-of-hearing viewers understand the full context.

6. Customize caption appearance — Adjust font size, background opacity, text color, and position to match your course branding and ensure readability. Apply styling settings across all videos in your course for consistency.

7. Add subtitles in additional languages — Repeat the caption process for each language you want to support. Learners will select their preferred language from the video player dropdown.

8. Publish or save captions — Click Publish or Save to finalize your captions. For longer videos, captions may appear in a "Pending Publish" status; allow processing time before the captions go live to learners.

Tips & Best Practices

• Use keyboard shortcuts to speed up manual caption entry: Command/Windows + Left/Right Arrow to seek backward or forward by 1 second, Command/Windows + Space to pause/play, and Command/Windows + Enter to add a new line.

• For AI-generated captions, always review the transcript for accuracy before publishing, especially in technical or specialized content where automated transcription may misinterpret terminology.

• Avoid captioning videos longer than one hour with manual or auto-sync methods; pre-made SRT files are more efficient for lengthy content.

• Include sound descriptions in captions—not just dialogue—to serve deaf and hard-of-hearing learners. Bracket descriptions like [background music fades] or [phone rings].

• Test caption display on mobile and desktop devices before releasing the course to ensure text is readable at all sizes and positions.

Troubleshooting

Captions don't sync with video audio

Check that your SRT or VTT file includes correct timestamp formatting (e.g., 00:00:01,000 --> 00:00:05,000). If using auto-sync, verify the transcript language matches the video's spoken language and audio quality is clear. Re-upload or re-paste the file.

Caption file upload is rejected

Confirm your file is in a supported format (SRT or VTT for most platforms). For VTT files, ensure the filename ends with .vtt and is saved as plain text with UTF-8 encoding. Check that the file is not corrupted and try uploading again.

Captions appear in "Pending Publish" and don't go live

This is normal for longer videos; the system is processing captions in the background. Wait 15–30 minutes and refresh the page. If status doesn't change, check platform notifications for processing errors or try uploading a smaller section of the video first.

AI-generated captions contain errors or misheard words

Use the built-in editor to manually correct each error. Click on the caption line, edit the text, and save. For recurring errors (e.g., technical terms), consider using a pre-made SRT file or adding a glossary alongside the video.

Multi-language captions don't appear in the video player

Verify that all caption files have been published (not in draft or pending status). Check that each language was assigned correctly during upload. Test the video player dropdown menu to confirm language options are listed and selectable.