Variable Frame Rate Checker
Check whether an MP4, MOV, or M4V video uses constant or variable frame timing — locally in your browser.
✓Only local file data is read. Your video is not uploaded.
✓ Free to use✓ No signup✓ Local analysis✓ Reads timing, not pixels
HOW IT WORKS
How to Use Motricialy Variable Frame Rate Checker
Add your video
Choose an MP4, MOV, or M4V file. The file stays on your device.
Read frame timing
The checker reads the video track’s MP4 timing table and compares stored frame durations.
Review CFR or VFR
See the frame-rate mode plus average, minimum, and maximum FPS values.
FEATURES
Key Features
CFR vs VFR Result
Separates constant timing from meaningful variation instead of guessing from a rounded FPS number.
Timing-Table Analysis
Reads MP4/MOV sample timing directly without decoding every video frame.
Min / Max FPS
Shows the frame-rate range derived from stored sample durations when timing varies.
Large-file Friendly
Reads container metadata instead of loading the whole video into memory.
Private by Design
Analysis happens in the current browser tab. The video does not need an upload.
Shareable Text Report
Copy or download a compact report for troubleshooting footage.
VFR EXPLAINED
Why Variable Frame Rate Can Matter in Editing
A video can average close to 30 or 60 FPS while individual frame durations still vary. Phones, screen recorders, webcams, and gameplay captures commonly produce this kind of timing.
CFRSteady frame timing
Frames use one dominant duration throughout the timing table.
VFRChanging frame timing
Multiple meaningful frame durations are stored in the video track.
ImportantVFR is not always bad
Convert only when your playback or editing workflow actually needs constant timing.
QUESTIONS
Variable Frame Rate Checker FAQs
How can I tell if a video is VFR or CFR?
Choose an MP4, MOV, or M4V file above. The checker reads the video track’s stored frame durations. Multiple meaningful durations produce a VFR result; effectively constant timing produces CFR.
Why can average FPS look normal on a VFR video?
Average FPS combines all frame timing into one number. A VFR file can average 29.97 or 30 FPS even when individual frame durations change.
Does VFR always cause audio sync problems?
No. Many VFR files play and edit normally. VFR is especially useful to check when you already see sync drift, stutter, proxy mismatch, or inconsistent timeline scrubbing.
Which files are supported?
This version focuses on MP4, MOV, and M4V files with a standard MP4/MOV video timing table. Fragmented MP4, MKV, and WebM are not supported.
Is the video uploaded?
No. The browser reads the file structure locally. The video is not uploaded to Motricialy for this check.