PostMicroTools
Utility
EXR sequence checker
Drag a folder or pick the files of an image sequence. The tool detects missing frames, inconsistent padding, duplicates and outlier sizes. Everything happens in your browser: nothing is uploaded.
How it works
Files are grouped by prefix and extension, and the last run of digits is read as the frame number. From that the expected range is computed and gaps are found. The analysis is of filesystem metadata (name and size); the image content is never decoded.
Why does padding matter?
Mixing shot.001.exr and shot.0001.exr in the same sequence breaks many readers (Nuke, Flame, ffmpeg). The tool warns about inconsistent zero-padding.
What is an “outlier size”?
A frame whose weight is far from the sequence median. It often indicates a black, half-rendered or corrupt frame. It's a hint, not a certainty.
The five-minute QC that saves a re-render
Render farms fail quietly. A 240-frame EXR sequence comes back from the farm, three frames died on a busy node, and nobody notices until the client review — where the missing frames flash as holes. Dragging the render folder into this checker takes seconds and reports exactly that: missing frames, inconsistent padding, duplicates and files whose size is suspiciously off from their neighbours (a 2 MB frame among 40 MB siblings is almost always a truncated write).
Padding inconsistencies are the sneaky one. A sequence mixing shot.0099.exr and shot.100.exr looks complete in a file browser but reads as two different clips in Nuke or Resolve, breaking the conform. The checker flags mixed padding before the sequence ever reaches a timeline.
Everything runs in your browser using the File System Access API — no frame is uploaded anywhere, which matters when the plates are under NDA. It works on any frame-numbered sequence: EXR, DPX, TIFF, PNG or JPEG.
Are my files uploaded to a server?
No. The check runs entirely in your browser; the tool reads file names and sizes locally and nothing leaves your machine. That's deliberate — VFX plates are routinely under NDA.
What counts as an anomalous file size?
Frames that deviate strongly from their neighbours in the same sequence. Content changes size gradually; a frame at a fraction of its neighbours' size usually means a truncated or failed write, and an exact-duplicate size pair can indicate a copied frame.
Which formats and naming patterns are supported?
Any sequence with a numeric frame token — name.####.exr, name_####.dpx, name.####.png and similar — including multiple sequences in one folder. EXR, DPX, TIFF, PNG and JPEG are the typical cases.