Free guide · Oct 15, 2026

FlashVSR: upscale video 4x and check for crawling detail

How to read the moving window, check for crawling detail, and follow the example from input to saved video.

The short version

FlashVSR is an open one-step diffusion model that upscales video 4x. The owners report about 17 FPS at 768x1408 on a single A100. Their long-video example takes one input file, upscales it, and writes one MP4 after the whole clip is done, so there is no live preview. The code and the v1.1 weights are Apache 2.0.

This guide shows you how to read the moving window, check for crawling detail, and follow the example from input to saved video. I read the README, the v1.1 model card and the example script line by line. I have not run it myself, so the speed numbers are the owners'.

What's in the full guide

  1. 01What this guide gives you
  2. 02Free first step
  3. 03Requirements and license
  4. 04Official setup
  5. 05Follow the example from input to saved video
  6. 06Read the moving window
  7. 07Step-by-step test
  8. 08Worksheet
  9. 09Read the result honestly
  10. 10Official sources

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