Get your PC games onto the TV without the guesswork.
Couch Lag is a free, guided troubleshooting and setup planner for streaming games from your gaming PC to your TV with Moonlight and Sunshine (and compatible hosts like Apollo and Vibepollo). It walks you through one safe, reversible change at a time for stutter, lag, black screens, HDR colors and controller problems.
- Tell it your host, client device, network and target resolution.
- Get a conservative starting point for resolution, frame rate and bitrate.
- Try one change, such as lowering bitrate about 25%, and record what happened.
- It suggests the next check, or a clean support report you can paste into a forum.
Plan, test one thing, compare.
Couch Lag doesn't install anything or read your devices. You tell it what you see, and it gives you rule-based next steps that link to the official Moonlight and Sunshine documentation.
Plan your setup
Pick your PC host software, your client (TV, Shield, Apple TV, Steam Deck and more), and your network. Get a starting configuration and a setup checklist. Using the Steam Link app or Steam Remote Play instead? Couch Lag is built for Moonlight; many network tips still apply, but settings differ.
Troubleshoot step by step
Choose a symptom and work through safe first-line checks one at a time. Log stutter incidents and Moonlight's on-screen stats to spot patterns.
Share a clean report
Export a plain-text support summary to paste where you ask for help. Couch Lag tries to hide emails, IP addresses, file paths and web links in your notes, but it can miss things such as names or PC names. Always read the report before you post it.
Couch Lag gives guidance, not guarantees. It can't measure your stream or prove a root cause, and some advice may lag behind new Moonlight or Sunshine releases. Always check the official docs before advanced changes.
Fixes for the problems people hit most.
Short, sourced answers based on the official Moonlight and Sunshine documentation, checked October 30, 2026. Each one can open the app with that problem already selected.
Moonlight stutters every few seconds
Hitches on a steady rhythm: stats overlay, Wi-Fi scans, Bluetooth, iperf3 and host-side checks.
Black screen but audio works
The stream connects and plays sound, but the picture stays black. Display, GPU, HDR and capture checks.
Sunshine error 503
What each of Sunshine’s three 503 messages means, read from its source code, and what to do.
Moonlight can’t find or reach your PC
The PC doesn’t appear or won’t connect: add by IP, firewall ports, VPNs and conflicting apps.
Washed-out or dark HDR
Washed-out or dark colours with HDR. Requirements, the Moonlight HDR switch, calibration and Apple TV Match Content.
No audio in Moonlight
No sound on the client, sound stuck on the PC, or PC audio missing after you stop streaming.
Streaming without a dummy plug
Why headless hosts fail and the options: dummy plug, virtual display, Apollo and Sunshine display settings.
Bitrate by resolution and frame rate
Moonlight’s default bitrates for 720p to 4K at 30–120 fps, from its source code, and when to go lower.
Steam Deck black screen
Deck as client or as Sunshine host: the 2026 Game Mode issues and what to try.
Best Moonlight settings for Apple TV
Every Apple TV Moonlight setting with its default, sensible starting values, HDR and Match Content.
Your answers stay on your device.
- The app runs entirely in your browser. Your answers, logs and readings are saved only in your browser's local storage.
- No accounts, no analytics, no tracking scripts, no ads, and no remote scripts or fonts.
- Nothing is submitted anywhere. Exports are files you download and choose whether to share.
- You can clear all saved progress from inside the app at any time.
Like any website, the web host and its network provider (Cloudflare) receive standard connection details, such as your IP address, when your browser loads these pages, and may keep them in short-term logs. Couch Lag adds no analytics or tracking of its own and never receives your answers.
Early and honest.
Couch Lag is an early beta (v0.9.5) from a small independent project. Expect rough edges. Anyone can try it: open the app and choose the 10-minute beta challenge. It's free, and there is nothing to buy or sign up for.