Burned-in or soft subs
Choose hardcoded captions permanently embedded in video, or separate subtitle tracks viewers can toggle on/off.
MP4 Subtitles
MP4 Subtitle Generator - Add Subtitles to Any MP4 File
Add subtitles to MP4 video files automatically with AI. Choose between burned-in (hardcoded) captions or soft subtitle tracks. Preserve original video quality, batch process multiple MP4 files, and export in any format. Free, no watermark.
MP4
native format support
Zero
quality loss on export
Free
no watermark
Features
Complete MP4 subtitle solution
Zero quality loss
Advanced encoding preserves your original MP4 quality. No re-compression artifacts or resolution reduction.
Batch MP4 processing
Upload multiple MP4 files and process them all at once. Same settings applied consistently across your batch.
SRT and VTT export
Export subtitles as separate SRT or VTT files alongside your MP4. Perfect for video players with track support.
Any resolution supported
4K, 1080p, 720p, or any resolution MP4. Subtitle sizing automatically adapts to your video dimensions.
Full style control
Custom fonts, colors, backgrounds, and positioning for burned-in subtitles. Professional results every time.
Workflow
How to add subtitles to MP4 files
Step 1
Upload your MP4
Drag and drop your MP4 file. Any resolution, any length, any codec supported.
Step 2
AI generates subtitles
Automatic speech recognition with 99%+ accuracy. Handles multiple languages and speakers.
Step 3
Choose export type
Burned-in MP4 with permanent captions, or original MP4 plus separate SRT/VTT subtitle file.
Step 4
Download your file
Export your subtitled MP4 with zero quality loss. Original resolution and bitrate preserved.
Use Cases
MP4 subtitle options explained
Burned-in (hardcoded)
Subtitles permanently embedded in the video. Works everywhere - any player, any platform, any device. Cannot be turned off.
Soft subtitles (SRT/VTT)
Separate subtitle file that plays alongside the video. Viewer can toggle on/off. Requires player support.
Multiple tracks
Generate subtitle files in multiple languages for the same MP4. Let viewers choose their preferred language.
Batch conversion
Process dozens of MP4 files at once. Apply consistent subtitle settings across an entire video library.
FAQ
MP4 subtitle generator FAQs
Will adding subtitles reduce my MP4 quality?
No. CapsAI uses advanced encoding to preserve your original video quality. No resolution loss, no compression artifacts.
What's the difference between burned-in and soft subtitles?
Burned-in subtitles are permanently embedded in the video pixels - they show everywhere but can't be toggled. Soft subtitles are separate files (SRT/VTT) that can be turned on/off in supported players.
Can I add subtitles to MP4 without re-encoding?
For soft subtitles (separate SRT/VTT file), yes - no re-encoding needed. For burned-in captions, minimal re-encoding occurs but quality is preserved.
What MP4 codecs are supported?
All common codecs - H.264, H.265/HEVC, VP9, AV1. If your MP4 plays on your computer, CapsAI can process it.
Can I batch process multiple MP4 files?
Yes. Upload multiple MP4 files and process them all with the same settings. Ideal for course creators and content libraries.
Add subtitles to any MP4 file in seconds
Burned-in or soft subs. Zero quality loss. Batch processing available. Free to use with no watermark.
Try CapsAI Free →