Automatically Generate, Translate and Edit Video Subtitles Online
Upload your video or audio and let EasySub automatically convert speech into timed subtitles. Review the text, translate subtitles, adjust timing and styles, then download your subtitles or export the final video.
Auto-Detect Language · Timed Subtitles · Bilingual Translation · Online Editing
EasySub: AI Subtitle Generator
AI Subtitle Generator is an automated subtitle generation tool. It uses speech recognition technology to convert spoken dialogue in videos or audio files into subtitles with a timeline.
With EasySub, you don’t need to transcribe each sentence manually. The system can automatically detect the video’s language, generate and translate subtitles, and allows you to edit the subtitle text, timing, font, color, and position on the screen.
How to Generate Subtitles with AI
To generate AI subtitles with EasySub, simply follow these four steps: upload, set the language, configure recognition, and edit and export. The entire process is completed online, with no need to transcribe each sentence manually.
Step 1: Upload Your Video or Audio
Upload the video or audio file you want to add subtitles to. We recommend using footage with clear audio and minimal background noise. The more stable the audio quality, the easier it is to review and edit the subtitles later.
Step 2: Select or Detect the Spoken Language
Select the original language of the video. If you’re unsure of the language, you can use the automatic detection feature. If you already know the language, we recommend selecting it manually to minimize misidentification.
Step 3: Choose Translation and Recognition Settings
If you need to translate the subtitles, enable the translation feature and select the target language. Then select the subtitle segmentation method: AI semantic segmentation, speech pause segmentation, or fixed-length segmentation.
Step 4: Edit and Export Your Subtitles
After the subtitles are generated, check the text and timestamps line by line. You can add, merge, or delete subtitles, and adjust the font, color, background, outline, and position. Once you’ve confirmed everything is correct, download the subtitles or export the video.
Everything You Need to Generate and Edit Video Captions
EasySub can automatically detect the original language of a video and generate subtitles with a timeline. If the video’s language is known, we recommend selecting it manually. This helps reduce errors in language detection.
If you need multilingual subtitles, you can enable the translation feature and select the target language. The system will generate both the original subtitles and the translated subtitles simultaneously, making it easy to create bilingual videos.
AI Subtitle Recognition and Translation Settings
| Setting | Function | Usage Recommendations |
|---|---|---|
| Auto Detect | Automatically detects the video’s original language | Use when the video’s language is uncertain |
| Spoken Language | Manually select the original language | Select this option when the language is known |
| Add Translation | Enable or disable subtitle translation | Disable this option when creating subtitles in the original language only |
| Translation Language | Select the target translation language | Cannot be the same as the original language |
| Original and Translated Subtitles | Generate both original and translated subtitles simultaneously | Suitable for courses, interviews, and multilingual videos |
Automatic recognition simplifies setup, but audio quality can still affect recognition results. Background noise, accents, multiple speakers, and technical terminology may all increase the amount of proofreading required. Therefore, you should still review proper names, brand names, and technical terms after subtitles are generated.
Three Subtitle Segmentation Modes
Subtitle segmentation determines where each subtitle begins and ends. Different modes are suitable for different video structures.
| Subtitle Segmentation Mode | How It Works | Recommended Applications |
|---|---|---|
| AI Model | Divides subtitles based on semantics and context | Tutorials, interviews, lectures, and long videos |
| Speech Interval Model | Divides subtitles based on pauses and intonation intervals | Speeches, podcasts, and conversational videos |
| Subtitle Length Model | Splits subtitles based on a fixed length | Videos requiring uniform subtitle lengths |
How to Choose a Subtitle Segmentation Mode?
1️⃣AI Model
Suitable for videos with continuous content and complete sentence structures. The system will attempt to segment subtitles based on semantics rather than solely on pauses.
2️⃣Speech Interval Model
Suitable for videos with clear pauses in speech. When the speaker pauses, the system divides the subtitles into new sentence segments.
3️⃣Subtitle Length Model
Suitable for projects requiring control over the length of individual subtitles. It ensures more consistent subtitle lengths but may sometimes split complete sentences.
The project settings page in EasySub offers these three subtitle segmentation modes. Users can select the segmentation method based on semantics, speech pauses, or fixed lengths.
Edit and Customize Your Subtitles
EasySub not only automatically generates subtitles but also provides a full-featured online subtitle editor. Users can edit subtitle content and apply uniform styling to all subtitles. Original and translated subtitles can be edited separately, making it ideal for bilingual video production.
Edit Subtitle Content Online
After generating subtitles, you can edit the text directly in the subtitle list. There’s no need to re-transcribe the entire video.
Supported editing operations include:
- Correcting incorrect text;
- Adding new empty subtitles;
- Merging the current subtitle with the next one;
- Deleting incorrect or duplicate subtitles;
- Swapping the order of bilingual subtitles;
- Showing or hiding original subtitles;
- Showing or hiding translated subtitles.
If the subtitles are split improperly, you can use the “Add” or “Merge” functions to reorganize them. The ORI and TRN toggles are used to control the display of the original and translated subtitles.
Customize Subtitle Styles
EasySub’s subtitle style editor allows you to modify the styles of the original and translated subtitles separately.
Adjustable options include:
| Style Setting | Main Function |
|---|---|
| Font Family | Change the subtitle font |
| Font Size | Adjust the text size |
| Text Color | Set the subtitle color |
| Opacity | Adjust the text opacity |
| Background Color | Set the subtitle background color |
| Outline Width | Adjust the text outline width |
| Outline Color | Set the outline color |
| Subtitle Position | Adjust the position of subtitles on the screen |
Style changes can be applied uniformly to the entire set of original or translated subtitles; there is no need to set them individually for each line.
Edit Bilingual Subtitle Styles Separately
EasySub uses ORI to denote original subtitles and TRN to denote translated subtitles.
The two sets of subtitles can be configured separately for:
- Font and font size;
- Text and background colors;
- Outline effects;
- Opacity;
- Vertical display position.
Users can also adjust ORI Y and TRN Y to change the height of the two sets of subtitles on the screen. This helps reduce overlap between bilingual subtitles and prevents subtitles from obscuring important parts of the video.
Recommended Subtitle Styles
For Chinese videos, the following settings are recommended:
- White text;
- Black outline;
- Outline width of 1 or 2;
- Transparent subtitle background.
These settings generally provide good clarity in most video scenes. For English-language videos or videos with complex backgrounds, you may want to keep the background semi-transparent. This enhances the contrast between the text and the video.
Specific styles should still be adjusted based on the video’s brightness, colors, and distribution platform. Don’t focus solely on visual appeal; ensure that the subtitles are clear and easy to read.
Visual Video Editor and Timeline
EasySub brings subtitle editing, video preview, and timeline control together in a single workspace. Users can directly adjust subtitles, text, images, and video clips. All changes can be previewed before exporting.
Preview and Adjust Video Elements
In the preview window, you can directly select the following elements:
- Subtitles;
- Standalone text;
- Images;
- Video frames.
Once an element is selected, you can drag, scale, rotate, and adjust its position. The properties panel on the right also allows you to set the X-axis position, Y-axis position, scale, and rotation angle.
These adjustments will be reflected in the final exported video. Therefore, you should check before exporting to ensure that subtitles do not obscure people, products, or important scenes.
Add Text and Images to Video
In addition to automatic subtitles, EasySub also supports adding text and images to videos.
Standalone text can be used for:
- Video titles;
- Names of people;
- Product models;
- Chapter titles;
- Key points;
- Calls to action.
The image feature can be used to add logos, product images, and other visual elements. After adding them, you can adjust their size and position in the preview window, or control their display duration via the timeline. Page 6 of the attachment shows the interface for adding text and images.
Change Aspect Ratio and Background
Users can adjust the video aspect ratio and background color based on the publishing platform.
| Video Aspect Ratio | Recommended Applications |
|---|---|
| 16:9 | YouTube, instructional videos, product demos, and landscape-oriented content |
| 9:16 | TikTok, Instagram Reels, YouTube Shorts, and vertical videos |
After adjusting to a vertical format, you should recheck the subtitle positions. Avoid having subtitles extend beyond the frame or be obscured by platform buttons.
Edit Subtitle Timing Online
The timeline is used to control the display duration of subtitles, text, images, and video elements.
Users can:
- Zoom in or out on the timeline;
- Select specific subtitles or on-screen elements;
- Adjust the start time of an element;
- Adjust the end time of an element;
- Control the duration of text and images;
- Manage the track order of different elements.
Text and images can be dragged directly onto the timeline. Except for the fixed subtitle track, text, images, and video elements can be moved up or down between tracks. Elements located higher on the timeline will be displayed first.
AI Subtitles for Different Video Types
EasySub is suitable for short videos, long videos, courses, and marketing content. Users can adjust the subtitle language, segmentation, style, position, and display duration based on the video type.
Automatically generate subtitles for tutorials, interviews, product reviews, and educational videos. Once the subtitles are generated, you can further edit the text, timing, and style to optimize them for landscape viewing.
Adjust the aspect ratio to 9:16 and use clear, eye-catching subtitles. Subtitle placement should avoid covering people, products, and platform control buttons.
Courses and Training Videos
Generate subtitles for online courses, how-to demonstrations, and corporate training. Clear subtitles help learners understand the content and make it easier to review key information later.
Interviews and Podcasts
Convert audio from interviews, podcasts, and speeches into subtitles. Choose an appropriate subtitle segmentation mode based on pauses in speech or semantic meaning.
Product and Marketing Videos
Generate multilingual subtitles for product presentations, advertisements, and social media videos. A single video can be produced in different language versions for multiple target markets.
Long Videos
Review long videos using the subtitle list and timeline. Users can edit subtitle content line by line, merge or delete subtitles, and adjust display times.
AI Subtitle Generator FAQ
Q1. Can AI Generate Subtitles from Video Automatically?
Yes. AI subtitle generators can recognize speech in videos or audio and convert it into time-stamped subtitles. You should still review the generated subtitles before exporting them, especially for proper names, brand names, and technical terms.
Q2. Should I Select the Video Language Manually?
If the video language is known, we recommend selecting it manually. This helps reduce language recognition errors. If you’re unsure of the original language, you can use the automatic detection feature.
Q3. Can EasySub Translate Video Subtitles?
Yes. After enabling the translation feature, simply select the target language to generate translated subtitles. The source language and target language cannot be the same.
Q4. Which Subtitle Segmentation Mode Should I Use?
Choose based on the video content:
- AI Model: Suitable for tutorials, interviews, and long videos;
- Speech Interval Model: Suitable for speeches or conversations with clear pauses;
- Subtitle Length Model: Suitable for videos requiring uniform subtitle lengths.
No single mode is suitable for all videos. Choose based on semantics, pauses, and subtitle length requirements.
Q5. Can I Edit Incorrect Subtitle Segments?
Yes. You can modify the subtitle text, as well as add, merge, or delete subtitles. If a sentence has been split incorrectly, you can merge adjacent subtitles; if a subtitle is too long, you can add a new subtitle line.
Q6. Can I Control Original and Translated Subtitles Separately?
Yes. Use “ORI” to control the original subtitles and “TRN” to control the translated subtitles. You can show, hide, and style each set of subtitles separately, as well as adjust their order and vertical position.
Q7. How Can I Prevent Bilingual Subtitles from Overlapping?
Adjust the positions of ORI Y and TRN Y separately. Place the original and translated subtitles at different heights, and check the preview window to ensure they do not obscure characters, products, or other important information.
Q8. Can I Change Subtitle Timing Online?
Yes. You can adjust the start and end times for subtitles, text, and images using the timeline. Zooming in on the timeline allows for more precise timing adjustments.
Yes. The subtitle editing interface provides a download option. Before downloading, you should complete text proofreading, time synchronization, and a review of the bilingual subtitles.
Q10. Can I Create Subtitles for Vertical Videos?
Yes. You can adjust the video aspect ratio to 9:16 for use on TikTok, Instagram Reels, and YouTube Shorts. After adjusting the aspect ratio, you’ll need to recheck the subtitle positions and sizes.
Q11. Are AI-Generated Subtitles Always Accurate?
Not necessarily. Recognition accuracy can be affected by background noise, accents, recording clarity, multiple people speaking at once, and specialized terminology. While AI can reduce the workload of transcribing, it cannot completely replace manual review.
Generate Captions for Your Video Now
Upload a video or audio file, select the source language, target language, and subtitle segmentation mode. EasySub will automatically generate subtitles. Afterward, you can review the text, adjust the timing, design bilingual subtitles, and download the subtitles or export the video.
