SubLayer — Universal Video Subtitles

Search subtitles online or load local SRT, WebVTT, and ASS/SSA files onto videos on any website.

SubLayer lets you search for subtitles online or load local subtitle files (.srt, .vtt, .ass, .ssa) onto any HTML5 video player across the web with frame-accurate synchronization. Whether a streaming player lacks captions in your language, has out-of-sync subtitles, or plays inside an embedded iframe or Shadow DOM, SubLayer attaches a clean, customizable subtitle overlay directly over the video. KEY FEATURES • Built-In Online Subtitle Search Search and load subtitles in one click right from the in-page control panel. Works out of the box with no API key required, and also supports an optional personal OpenSubtitles API key in Settings. • Local Subtitle File Support (.srt, .vtt, .ass, .ssa) Drag and drop a subtitle file directly onto the control panel or browse from your computer. Automatically detects UTF-8, UTF-16, and legacy character encodings (Arabic Windows-1256, Cyrillic Windows-1251, Greek, Hebrew, Japanese, Chinese, Korean) with instant one-click re-decoding. • Universal Video Compatibility Works on standard HTML5 <video> elements, custom players inside open or closed Shadow DOM roots, same-origin and cross-origin embedded iframes, fullscreen mode (via top-layer rendering), and dynamically replaced video players. • Frame-Accurate Synchronization & Live Offset Controls Synchronizes cues using requestVideoFrameCallback. Easily nudge subtitle timing forward or backward (-0.5s, -0.05s, +0.05s, +0.5s) or type an exact offset in seconds or milliseconds. • Full RTL & Bidirectional Language Support Properly renders Arabic, Hebrew, and Persian subtitles with per-line bidirectional text isolation and a bundled Noto Naskh Arabic variable font. • Fully Customizable Appearance Open Settings to customize font size (% of video height), font family, text and background colors, background opacity, text outline/shadow style, bold weight, bottom margin, and alignment with a live real-time preview. • Privacy-First & Zero Telemetry SubLayer has zero analytics, tracking, or background scripts running on your browsing history. It activates only when you click "Activate on Page", and only makes network requests when you explicitly search for subtitles online. HOW TO USE 1. Open any webpage with a video and click the SubLayer icon in your Chrome toolbar. 2. Click "Activate on Page" (or use "Pick Video" to click a specific player). 3. In the floating SubLayer panel on the video, search for subtitles online or drag and drop a local .srt, .vtt, .ass, or .ssa file. 4. Use the panel or keyboard shortcuts to adjust timing or toggle visibility. DEFAULT KEYBOARD SHORTCUTS • Toggle subtitles: Alt+Shift+V • Delay subtitles (-100ms): Alt+Shift+Comma • Advance subtitles (+100ms): Alt+Shift+Period