Video Subtitle Adding Tool

1Upload Video

Click the upload area or directly drag video files to the page. Supports common video formats such as MP4, AVI, MOV, WebM, MKV.

2Add and Edit Subtitles

Click the "Add Subtitle" button in the right panel to create a new subtitle. The interface is divided into two tabs:

• Subtitles Tab：
  • Edit subtitle text directly in the subtitle list
  • Click on a subtitle item to jump to the corresponding time point and select that subtitle
  • Click the "+" button on the right side of a subtitle item to insert a new subtitle after that one
  • Click the "×" button to delete a subtitle
• Subtitle Toolbar Functions（位于字幕列表下方）：
  • Add Subtitle：Add Subtitle: Manually create a new subtitle entry
  • Upload SRT：Upload SRT: Upload an SRT format subtitle file, automatically parse and import all subtitles (supports standard SRT format)
  • Download SRT：Download SRT: Export all current subtitles as an SRT format file for use in other tools
  • Copy Subtitles：Copy Subtitles: Copy all subtitle text to clipboard for quick copying
  • AI Parse Subtitles：AI Parse Subtitles: Automatically recognize speech content in video and generate subtitles (only supports videos within 1 hour)
• Styles Tab：Adjust style settings, will be applied to all subtitles
  • Font Size：Font Size: 12-72 pixels
  • Font Color：Font Color: Select using color picker
  • Position：Position: Top/Center/Bottom
  • Background Shadow Intensity：Shadow Intensity: 0-3 levels, enhance subtitle visibility
  • Note: Style settings will be uniformly applied to all subtitles, individual subtitle configuration is not supported

3Adjust Subtitle Time Using Timeline

The timeline provides an intuitive way to manage subtitle timing:

• Click timeline: Jump to corresponding time point
• Drag subtitle block: Move the entire subtitle time period
• Drag left edge of subtitle block: Adjust subtitle start time
• Drag right edge of subtitle block: Adjust subtitle end time
• Click subtitle block: Select subtitle and jump to start time
• Zoom control: Use the zoom slider in the top right corner to adjust timeline display scale

4Preview Subtitle Effects

Use the video player to preview subtitle effects:

• Play/pause button controls video playback
• Rewind/forward buttons can quickly jump 5 seconds
• Mute button controls audio on/off
• Subtitles will be displayed in real-time on the video during the set time period
• You can adjust subtitle styles while playing and view effects in real-time

5Export Video

After confirming subtitle settings are correct, click the "Export Video" button to start processing. Progress bar and estimated remaining time will be displayed during processing.

Note: Processing time depends on video length, resolution and number of subtitles.

6Download Video

After processing is complete, click the "Download Video" button to save the video file with subtitles. The filename will automatically add "_with_subtitles" suffix.

Q1: Will videos be uploaded to the server?

A1: Video processing (adding subtitles, exporting videos) is completely done locally, video files are not uploaded to the server. However, if you use the AI parse subtitle function, the system will extract audio from the video and convert it to base64 format before sending it to the server for speech recognition processing. After processing is complete, the server will return recognition results. We recommend not using videos containing sensitive information for AI parsing.

Q2: Is this tool free? Will processed videos have watermarks?

A2: Completely free, and processed videos will not have any watermarks added. You can use it with confidence, all features are free, the generated videos are completely yours, with no brand identifiers or watermarks.

Q3: What video formats are supported?

A3: Supports common video formats such as MP4, AVI, MOV, WebM, MKV. It is recommended to use MP4 format for best compatibility and processing speed.

Q4: How long does it take to process videos?

A4: Processing time depends on video length, resolution and number of subtitles. Usually 1 minute of video requires 1-3 minutes of processing time. Progress bar and estimated remaining time will be displayed during processing.

Q5: How many subtitles can be added?

A5: Theoretically, unlimited subtitles can be added. Each subtitle can have different time periods, positions, colors and styles. It is recommended to add reasonably according to video content to avoid too many subtitles affecting viewing experience.

Q6: Does it support Chinese subtitles?

A6: Yes, it fully supports Chinese. The tool uses font files that support Chinese, and can normally display Chinese, English and other characters.

Q7: Will video quality decrease after processing?

A7: We use high-quality encoding settings (CRF 23) to maintain original video quality as much as possible. Video quality loss after processing is minimal, usually imperceptible to the naked eye. If you have higher quality requirements, you can try using original high-quality video files.

Q9: What to do if processing fails?

A9: If processing fails, please check the following: 1) Ensure the video file is complete and format is correct; 2) Check if subtitle timing settings are reasonable (start time is less than end time); 4) Please try refreshing the page or using other video files.

Q10: How to upload SRT subtitle files?

A10: In the subtitles tab, click the "Upload SRT" button and select your SRT format subtitle file. The system will automatically parse the file content and import all subtitle entries, including timecodes and text content. Uploaded subtitles will automatically apply current global style settings.

Q11: How to export subtitles as SRT files?

A11: In the subtitles tab, click the "Download SRT" button to export all current subtitles as a standard SRT format file. The exported file can be used in other video editing software for subtitle reuse and backup. If there are no subtitles, this button will be disabled.

Q12: How to copy subtitle text?

A12: Click the "Copy Subtitles" button, and the system will concatenate all subtitle text content and copy it to the clipboard. This function allows you to quickly obtain all subtitle text for other purposes (such as translation, proofreading, etc.). If there are no subtitles, this button will be disabled.

Q13: How to use the AI parse subtitle function?

A13: The AI parse subtitle function can automatically recognize speech content in videos and generate subtitles. How to use: 1) Ensure video duration does not exceed 1 hour; 2) Click the "AI Parse Subtitles" button; 3) The system will automatically extract video audio and call the AI interface for speech recognition; 4) After recognition is complete, subtitles will automatically be filled into the subtitle list. Processing time depends on video length, usually 1 minute of video requires 10-30 seconds.

Q14: Why does the AI parse function only support videos within 1 hour?

A14: To ensure processing speed and stability, the AI parse function has a 1-hour limit. If your video exceeds 1 hour, it is recommended to use video editing software to split it into multiple shorter segments, then use the AI parse function separately. Or, you can first use AI parsing to generate partial subtitles, then manually add the remaining parts.

Q15: How accurate are AI parsed subtitles?

A15: AI parsing uses advanced speech recognition technology with high recognition accuracy. However, accuracy will be affected by factors such as video audio quality, background noise, speaker speed and accent. It is recommended to use clear, noise-free video files for best recognition results. After parsing is complete, you can manually edit and adjust subtitle content.

Q16: What to note when uploading SRT files?

A16: Uploaded SRT files need to conform to standard SRT format: each subtitle segment contains a sequence number, timecode (format: HH:MM:SS,mmm --> HH:MM:SS,mmm) and text content, with blank lines separating segments. If the file format is incorrect, the system will prompt an error. After successful upload, subtitles will automatically be sorted by time.