Download 4.2.0 · Getting started · Documentation · Release notes · Website
Frame Warp
Turn the camera and the picture turns on your screen's next refresh, instead of a round trip and the game's own delay later. Nightjar shifts each picture by the turn your mouse or right stick has made since the PC drew it. Rubylight learns, for the game you are playing, how far the picture moves per input and how long the game takes to show it, and keeps the HUD where it is.
- 96% of the trail gone. A test game with 50 ms of delay, streamed at 1440p and 60 fps, showed the picture a median 64.9 px behind the mouse while turning. With Frame Warp: 1.4 to 2.2 px.
- Learns each game by itself. Sailing in Black Flag Resynced, streamed to a handheld and a laptop, it learned the camera as it turned and kept the quest text, compass and icon wheel in place.
- Right out to the edges. It learns each game's field of view and turns the picture the way the game's camera would. At a 90° view, 91% of the trail is gone at the picture's edge, up from 65% when the whole picture slid by one shift (Rubylight 4.1 and Nightjar 5.1).
- Costs almost nothing. 0.14 to 0.16 ms of GPU time a frame on the RX 7900 XT, from 1080p to 4K.
- One switch. Nightjar › Settings › Video › Frame Warp. Rubylight is ready for it out of the box.
How Frame Warp works · Measurements · The lens
Real VRR
With VRR, your screen refreshes whenever a frame arrives, so it follows the network's rhythm rather than the game's. With Real VRR, Nightjar shows each frame at the moment the game presented it on the PC, plus a short, steady delay, and the screen refreshes in step with the game. Rubylight stamps every frame with the game's present time, and for a VRR stream runs the virtual display at 1000 Hz so each frame leaves the moment it is drawn.
- 97% of frames on the game's rhythm, instead of 81 to 90% shown on arrival, for 1.3 to 1.5 ms of delay. PyroWave, HEVC and AV1 alike, measured on the same PC.
- Holds up on Wi-Fi. A frame much later than the rest is shown when it is ready instead of holding every frame back for it, so over Wi-Fi it halves the frames off the rhythm for 2.6 to 4.2 ms.
- On by default in Nightjar whenever Variable refresh rate is on: a G-Sync, FreeSync or HDMI VRR display on Windows and Linux, or an Android 16 screen with adaptive refresh.
How Real VRR works · Measurements
What's new
Rubylight 4.0 covers everything since 3.0. Nightjar 5.0 is the matching client. Release notes
- A calmer console. Home opens on pairing for a new PC and lists what needs attention, each with a button that fixes it. All settings has six tabs, Ctrl+K finds any game, device, setting or action, and restarting Rubylight, display recovery and crash reports moved to Advanced › Troubleshoot.
- NVIDIA graphics cards, with their driver settings. NVENC encodes H.264, HEVC and AV1, with native YUV 4:4:4 where the encoder offers it. A game's Graphics driver panel and Nightjar's stream menu set NVIDIA's Low Latency Mode, Max frame rate, Vertical sync, Smooth Motion and more, and put the PC's own values back when the session ends. Peak bitrate sets how far variable bitrate may go, and NVIDIA Reflex is an RTSS limit mode again. NVENC
- Move a game between devices, or use two screens. Continue here moves the stream while the game keeps running; Stream here too joins it. Nightjar's Dual screen mode gets a second virtual display, or the PC's other physical monitor.
- Play in a browser and invite friends. A PIN-paired play page for browsers, TVs and consoles, plus guest links with access controls; H.264, HEVC and AV1, with HDR where supported. Browser streaming
- Every launcher works like Steam. Epic Games, Battle.net, Microsoft Store and Xbox, EA app, Ubisoft Connect, GOG and your game folders each sync on their own terms, and each device can keep its own copy of a game's settings files. Managed game files
- More controller choices. A Steam Controller (2026) profile with trackpads, back grips, motion and haptics, plus Xbox 360 (ViGEmBus) for tools such as reWASD that look for a USB controller.
- Manage the PC from the couch. Authorised Nightjar devices can approve another device's pairing, restart or shut down an idle PC, install a pending host update, and serve as the PC's microphone with no stream. Permissions control each action.
- Frames leave sooner. 4K frames go out slice by slice, large frames start leaving before the whole frame is ready, and streams stay timed to the device's refresh after the PC was busy.
Why Rubylight
A closer look
Ready to play in minutes
Open https://localhost:47990 on the PC and Home walks you through pairing and your first game. Nightjar pairs by scanning a QR code; Moonlight with a PIN. While you play, Home shows the stream's frame rate, bitrate and encoder timing, and what the host changed and why.
This is the beginning of the README. Read the rest at the original. Read the full README ↗
