How It Was Built

How ShadePlay was built

From "ShadowPlay is unreliable" to an always-on recorder with a one-click installer: every problem we ran into, what we found, and how we fixed it.

About this page

ShadePlay is an always-on instant-replay screen recorder for Windows. It keeps the last minute of your screen and sound in memory, all the time, and saves it as a video when you press F10. It was built to replace NVIDIA's Instant Replay (often called ShadowPlay) on one gaming PC, and then made ready for everyone.

"We" means the maintainer (baddo) and Claude, an AI model made by Anthropic. The maintainer set the goals, made the key decisions, ran every hands-on test on their own gaming PC and chose the name. Claude researched the Windows, graphics-card and FFmpeg details, wrote the design, the code and the automated tests, measured the results and explained each step. Anthropic does not publish, endorse or support ShadePlay.

This page follows the transparency promise of the README, so it has a section on when the AI got it wrong, too. The maintainer asked for it while preparing the release: a "detailed wiki, why we did it, transparent AI use".

Where the rest lives. The README is the short version. The ShadePlay guide explains the app itself. ARCHITECTURE.md describes how it works inside, and BUILDING.md how to build it from source.

How to read it. Each problem is a short entry: Problem, then What we found, then Fix. Quotes are the maintainer's own words, with the spelling tidied, unless they are marked as Claude's. All dates are in September 2026. Numbers were measured on the test PC described in The setup, unless an entry says otherwise.

Contents

• When it happened
• Part 1: why ShadePlay exists
• Part 2: how we worked, including when the AI got it wrong
• Part 3: the picture
  • Chapter 1: capturing the screen
  • Chapter 2: colour and compression
• Part 4: sound, saving and the app
  • Chapter 3: every sound, counted once
  • Chapter 4: the replay and the save
  • Chapter 5: an app that just works
  • Chapter 6: YouTube without a Google app
  • Chapter 7: more graphics cards
• Part 5: making it shareable
• Part 6: what is still open
• Glossary
• Tell us how it works for you

When it happened

When	What happened
September 24	The maintainer's first message: "ShadowPlay is unreliable". Research with a skeptical second check, small test programs on the real PC, the design, the first recorder and its first adversarial review, all on the same day. The first real HDR clip. F10 becomes the hotkey. The maintainer switches NVIDIA's Instant Replay and its overlay off. A settings window goes on the list. 331 automated tests.
September 27	The maintainer starts the recorder for the first time. A Game track and a settings window come first, then the first hands-on test in a real game passes. "Always record". Doubled audio is found in real use and fixed the same day. YouTube research, and a browser helper instead of a Google sign-in. HDR on YouTube is settled, and clips upload as they are. AMD and Intel research. The name ShadePlay and the decision to go public. "Too complicated": one simple settings page. The README's "Why I made this". The release preparation starts.
September 28	The first release work finishes: the new name everywhere, a move-over for the private install, a one-click installer, experimental AMD and Intel encoders, an encoder test for testers, a privacy scrub, and a GPL surprise inside the FFmpeg DLLs. 602 tests. The maintainer chooses ShadePlay's own FFmpeg build and version 0.1.0. More release preparation: a restart loop with a sleeping monitor is fixed, Send feedback joins the tray menu, and work starts on the update checker, the guide and this page.

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Contents | Part 1: why ShadePlay exists ->