Free Online Transparent Video & Alpha Channel InspectorAlpha detector
Launch VideoBGAlpha to verify whether your WebM, MOV, or MP4 file contains real alpha transparency before shipping to production. Inspect both container metadata tags and decoded RGBA pixel coverage 100% locally.
Local source video
The file is copied into the browser FFmpeg Worker only for local probing and decoding.
Local detector limit: 200 MB · 60s · long edge 1920 · short edge 1080 · 30 fps
Transparency scan
Sampled detection is the default. Full detection decodes the complete supported video and does not extrapolate from samples.
Playback background check
Switch backgrounds to visually inspect playback. The formal result below still comes from decoded alpha pixels, not from how a native player happens to render the file.
Evidence layers
Sampled detection is the default. Full detection decodes the complete supported video and does not extrapolate from samples.
Safe HTML embed example
The sample uses a replaceable public URL and never copies the local blob URL or a private signed download link.
<video controls playsinline preload="metadata" style="background: transparent;">
<source src="https://example.com/your-transparent-video.webm" type="video/webm">
Your browser does not support this video format.
</video>01 / WHY CHOOSE THIS PRESET
3s preview validation, 7-day mask reuse & transparent billing
Test 3 Seconds Before Full Render
Cloud presets can preview the first 3 seconds: 3 credits for automatic cutout or one blur target, 6 credits for faces and plates.
0-Credit Restyling & Blur Tuning
Cloud masks and tracking paths are cached for 7 days—swap backgrounds or adjust blur radius and feathering at zero extra AI cost.
Cloud AI or 100% Free Local WebGL
Use cloud AI for natural backgrounds and privacy tracking, or switch to our 100% free browser-local WebGL chroma keyer and alpha inspector.
100% Automatic Credit Release
If a face, license plate, or screen blur job detects zero targets in your clip, reserved credits are released automatically.
02 / HOW TO USE · THREE-STEP WORKFLOW
Standardized workflow from source clip to verified export
Select WebM, MOV, or MP4 Video Locally
Choose any video file up to 500 MB. It stays 100% in your browser memory without uploading.
Run 16-Frame Sampled or 900-Frame Full Scan
Use Quick Sampled Scan (up to 16 frames) for instant triage or Full Frame Scan (up to 900 frames, 180s) for complete verification.
Review Dual Diagnostic Report & Copy HTML5 Code
Inspect container alpha tags, decoded RGBA transparency ratios, checkerboard preview, and ready-to-use `<video>` embed code.
03 / TYPICAL USE CASES
Where teams deploy this preset
Pre-Deployment QA for Hero Transparent Videos
Confirm VP9 WebM and HEVC MOV files actually decode with `alpha < 255` before pushing landing pages live.
Catch Baked-In Checkerboards & Opaque Exports
Verify freelancers or render farms delivered true alpha channels rather than RGB videos with gray-and-white grids.
Diagnose Container vs. Browser Decoder Mismatches
Distinguish whether a black background bug is caused by missing alpha metadata or an unsupported browser codec.
04 / FREQUENTLY ASKED QUESTIONS
Questions about this workflow
Why does my transparent video show a black background on a webpage?
Either the exported file lost its alpha channel during encoding, or the browser does not support alpha decoding for that container (for example, standard H.264 MP4 does not support native alpha).
How does VideoBGAlpha detect "fake" transparent videos?
Many tools only check container flags. VideoBGAlpha also decodes video frames onto an offscreen RGBA canvas and checks whether pixels actually have `alpha < 255`.
What is the difference between 16-frame sampled and 900-frame full scan?
Sampled mode probes up to 16 evenly spaced frames for fast verification, while Full mode scans up to 900 frames (180 seconds) to catch intermittent alpha dropouts.
Is my video uploaded anywhere during inspection?
No. All metadata probing and frame decoding happen 100% locally in your browser.
Which video formats support true transparency on the web?
WebM (VP8/VP9 with `alpha_mode=1`) for Chrome/Edge/Firefox, and MOV/MP4 (HEVC with alpha or Apple ProRes 4444) for Safari/Apple devices.
Does this inspector cost any credits?
No. It is 100% free with no login required.
05 / ALL 8 VERIFIED PRESETS (4×2 SYMMETRIC MATRIX)
Explore all 8 specialized video preset pages
Remove Video Background
Start a fresh AI background-removal project without restoring an older workspace.
Blur License Plates in Video
Open VideoBGBlur with license-plate detection selected.
Blur Screens in Video
Open VideoBGBlur with the verified screen target selected.
Blur Faces & License Plates
Auto-track and blur both faces and vehicle license plates in one outdoor pass.
Remove Green Screen from Video
Open the browser-local chroma-key tool with the green preset selected.
Remove Blue Screen from Video
Open the browser-local chroma-key tool with the blue preset selected.