Free AI Caption Generator

This browser-based caption tool helps creators, editors, and teams generate, edit, style, and export captions without uploading source media to a server or creating an account. It runs locally in the browser, keeps files on your device, and produces watermark-free exports for social, editorial, and video workflows.

The tool supports both video and audio projects, letting you generate captions, review and edit transcripts, customize their appearance, and export finished captioned videos or subtitle files. It works with formats including MP4, MOV, WebM, MP3, WAV, M4A, and AAC, with support for vertical, square, and widescreen content.

Key Features

Local Caption Generation

Generate captions directly in the browser without sending your source media to a remote service.

• Process video and audio locally
• Keep source files on your device
• No account required
• No server-side media upload
• Watermark-free exports

Caption Styles

Customize how captions look before and after generating them.

• Preset caption styles
• Adjustable fonts and colors
• Control spacing and positioning
• Background customization
• Motion and animation effects
• Save custom styles for reuse

Multiple Export Options

Export captions in formats suited to different publishing and editing workflows.

• Captioned MP4
• Plain transcripts
• SRT subtitles
• Word-timed SRT
• WebVTT
• Transparent caption layers
• Split alpha layers for additional editing control

Manual Caption Editing

Work with existing subtitle files or refine automatically generated captions.

• Import existing SRT files
• Edit caption text
• Adjust timings
• Review generated transcripts
• Refine captions before export

Social-Ready Video Layouts

Prepare captioned content for common social and editorial formats.

• Vertical video
• Square video
• Widescreen video
• Punch-in motion
• Video-in-type effects
• Captions positioned behind the subject

Transparent Caption Layers

Export captions separately when you want more control in another video editor.

• Transparent background exports
• Alpha caption layers
• Split layers for advanced workflows
• Designed for compositing and further editing

Audio Captioning

The tool also works with audio-only files, making it possible to generate captions and subtitle files without starting with a video.

• MP3 support
• WAV support
• M4A support
• AAC support
• Transcript generation from spoken audio

Built For Private Caption Workflows

The tool is designed for creators and editors who want captioning without adding another upload-based service to their workflow.

It is particularly suited to:

• Content creators producing social videos
• Video editors preparing subtitles and caption layers
• Podcasters turning audio into captioned content
• Marketing teams creating short-form campaigns
• Agencies handling client media
• Privacy-conscious teams working with sensitive footage

Common Use Cases

Creating Social Captions

Generate and style captions for vertical, square, and widescreen videos before exporting them for social platforms.

Preparing Subtitle Files

Create SRT or WebVTT files for videos that need standalone subtitle tracks rather than burned-in captions.

Captioning Podcasts and Audio

Turn spoken audio into editable transcripts and subtitle files without first converting the audio into video.

Editing Existing Subtitles

Import an existing SRT file, review the text and timings, and make adjustments before exporting.

Creating Editor-Ready Caption Layers

Export transparent caption layers when you want to bring the finished caption design into another video editing workflow.

Local Captioning Without Uploads

The tool keeps the captioning workflow inside the browser. Instead of uploading source footage to a cloud service, media, transcripts, and related editing data stay on the device during the workflow.

That makes it useful for projects where source footage needs to remain private or where you simply want to avoid creating an account and uploading files before getting started.

Flexible Caption Styling

Caption generation is only part of the workflow. The editor also gives creators control over how captions appear in the finished video.

You can adjust typography, colors, spacing, backgrounds, motion, and positioning, while effects such as punch-in motion and subject-aware caption placement provide more visual options for short-form content.

The ability to add Google Fonts stylesheets and save styles as JSON also makes it easier to reuse a consistent caption treatment across projects.

Export For Different Workflows

The tool supports both finished-video exports and assets intended for further editing. You can create a captioned MP4 for direct publishing, export subtitle files such as SRT and WebVTT, or create transparent caption layers for use in another editor.

That flexibility makes it suitable for workflows where captions need to be published immediately as well as projects where an editor wants more control over the final composition.

Why It Matters

Captioning often involves several separate steps: transcription, timing corrections, visual styling, subtitle export, and final video rendering. Moving between different tools can make a simple captioning task unnecessarily slow, especially when source media needs to remain private.

This browser-based workflow brings those steps together while keeping processing local. You can generate captions, refine them, style them, and export the result without an account, cloud upload, or watermark.

Create Private, Editable Captions in Your Browser

Generate, edit, style, and export captions for video and audio locally in your browser, with subtitle files, captioned MP4s, transparent layers, and no account or watermark required.