Caption text layers
Add caption blocks as ordinary text layers, so they share styling controls with titles and lower thirds.
Add Subtitles To Video Online
Add Subtitles to Your Videos Online – Generate AI Captions Automatically or Manually. Export in 4K, No Watermark, No Limits, and 100% Free
Upto 4K Free & Watermark-Free Exports
Export your video creations in stunning high-definition resolution up to ultra-sharp 4K completely free of any restrictive watermarks. Enjoy a professional, native-level editing experience with absolutely no file limits, local project autosaving, and total sandbox privacy.
Automatic Subtitle Generator
Convert speech to readable text instantly. Our highly accurate transcriber processes spoken audio inside your video, generating perfectly timed subtitle blocks automatically to save you hours of manual transcription work.
500+ Custom Typography Styles
Design beautiful, highly engaging social captions. Select from hundreds of premium font options, thick outline text borders, colored badge backdrops, lower third templates, and visual alignment presets to fit your branding style.
SRT & VTT Subtitle File Import
Enjoy complete flexibility. Import existing subtitle tracks (.srt, .vtt) to instantly display them on screen, or export your edited timeline captions as standalone files to upload directly to YouTube, Facebook, or LinkedIn.
Burned-In Social Media Captions
Ensure your message is read on every mobile platform. When you trigger an export, our WebGL compositor flattens the vector styling directly into the video stream, burning in high-contrast captions that work perfectly without player configurations.
Frame-Accurate Caption Snapping Timeline
Fine-tune caption timing with frame-accurate precision. Drag the handles of individual subtitle blocks to match verbal cues, or split text segments to keep layout cards readable on small screen displays.
Precision Keyframe Animation Paths
Animate any visual property dynamically over your timeline. Easily place keyframes on visual tracks to control custom movement paths, scale zoom factors smoothly, adjust opacities gradually, or rotate graphic elements over time.
Creative Color Grading & Pro Filters
Perfect the mood and style of your footage with granular control. Adjust exposure levels, tweak visual contrasts, refine saturation depths, highlight ranges, and shadow intensities, or apply artistic color filters in seconds.
Granular Audio Mixing & Volumes
Master your project soundtracks like a professional sound engineer. Layer voiceovers against background music, set custom fade-in and fade-out durations, adjust individual track decibels, or mute unwanted noises instantly.
Zero-Upload Local Sandbox Privacy
Keep your personal video captures and creative media 100% private. Because Klipworm composite, decodes, and encodes files entirely inside your local browser container sandbox, your raw files are never uploaded to servers.
How It Works
Klipworm runs entirely in your local browser sandbox. Follow these four simple steps to edit your media.
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1
Import Video Media
Upload your clip into the subtitle workspace to render it locally on the player.
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2
Write and Align Captions
Add subtitle blocks, write your text, and adjust the timeline tracks to match audio cues.
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Render and Download
Compile the project to burn the styled subtitles directly onto the canvas before downloading.
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Export & Download in 4K
Compile your custom timeline modifications instantly within the browser, rendering high-definition, watermark-free video files ready for direct device download.
What you get
Features engineered for high performance, local execution, and total data safety.
Timing control
Adjust the in and out point of each caption on the timeline to keep it in sync with the audio.
Readable social video styles
Pick text styles tuned for vertical and square video where caption legibility matters most.
Common use cases
How creators use this tool in their active visual workflows.
- Caption a podcast clip for social
- Add lower thirds to interview footage
- Make a tutorial accessible to deaf and hard-of-hearing viewers
- Localize a short video with translated captions
Supported formats
Klipworm works with standard professional web containers.
MP4WebMSRTVTT
Local Processing Guaranteed
All operations are executed on your local CPU and GPU. None of your media is sent to a backend queue, ensuring complete security and zero bandwidth cost.
Frequently Asked Questions
Have questions about our add subtitles tool? Find the answers below.
Q.Can I style subtitles?
Yes. You can adjust text, position, style, and timing for caption overlays.
Q.Can I use subtitles for short-form videos?
Yes. Vertical and square formats are supported for reels, shorts, and posts.
Q.Will subtitles be hardcoded into the exported file?
Yes. The canvas compositor draws the caption styling directly onto the frames, burning them in so they are visible on all social platforms.
Q.Can I export standalone subtitle files?
Klipworm is structured to support subtitle formats like .srt and .vtt, letting you download standalone files.
Q.How do I time captions accurately?
Use the interactive timeline handles to drag the start and end of each caption block to match your spoken audio.
Q.Will my caption work be saved if I close the tab?
Yes. Klipworm debounces timeline metadata and autosaves your subtitle tracks to localStorage, keeping your progress fully secure.
Q.Is there any hidden subscription fee or watermark on the exported files?
Absolutely not. Klipworm is completely free to use. All of our browser-based video editing and export features—including high-definition rendering up to 4K—are watermark-free and have no hidden usage limits or recurring subscription costs.
Q.Does this tool require installing software or browser plugins?
No. Klipworm is a native, web-based tool. It runs entirely inside your active browser sandbox using web standards like WebGL and WebAssembly. You do not need to download, install, or configure any external applications or browser extensions.
Q.Can I continue editing my projects offline without an active internet connection?
Yes. Since all decoding, editing, and rendering engines operate directly on your computer's local hardware (CPU/GPU) within your browser session, you can adjust your timelines, edit parameters, and compile files even if you go completely offline.
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More browser-based video tools that pair well with add subtitles.
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