ShaderGlass is free, it is GPLv3, and it carries the entire libretro shader library (more than 1200 presets) into a floating window you can park over DOSBox, a browser video, or Aseprite. It sits at 96 percent positive on Steam for good reason. Then you launch something from the last decade in exclusive fullscreen and the illusion stops, because ShaderGlass captures the desktop rather than hooking the renderer, and exclusive fullscreen is not capturable. The ShaderGlass alternatives below split that job three ways: injectors that live inside the game’s render pipeline, window scalers built on the same capture approach, and the emulator that owns the shader library in the first place. All seven run on Windows and all seven shipped updates this year.
Quick comparison
| App | Best for | Cost | Works with | Standout |
|---|---|---|---|---|
| ReShade | Filters inside modern games | Free | D3D9 to D3D12, OpenGL, Vulkan | Runs in exclusive fullscreen with depth buffer access |
| Magpie | Free window overlay closest to ShaderGlass | Free (GPLv3) | Any windowed or borderless app | FSR, Anime4K, CuNNy, CRT_Geom and CRT_Easymode in one tool |
| RetroArch | The shader library at its source | Free (GPLv3) | Content running in libretro cores | Multi-pass slang presets including crt-royale |
| Lossless Scaling | Scaling and frame generation | $6.99 on Steam | Any windowed or borderless app | LSFG 3.1 frame generation on almost any GPU |
| Special K | Fixing the frame before filtering it | Free (GPLv3) | D3D11 and D3D12 games | HDR retrofit with a configurable tone mapper |
| NVIDIA app | Zero-install filters on GeForce | Free | Driver-supported game list | RTX HDR and RTX Dynamic Vibrance from the overlay |
| mpv | Shaders on video instead of games | Free (open source) | Local and streamed video | GLSL user shaders including Anime4K modes A, B and C |
Why people look for ShaderGlass alternatives
Exclusive fullscreen is off the table. ShaderGlass captures a window or the desktop, so a game holding an exclusive fullscreen swapchain is invisible to it. The workarounds are running the game windowed, switching it to borderless, or forcing borderless with something like dgVoodoo2 first.
Windows 10 gets a yellow box. The capture border is a Windows security feature. The option to remove it only works on Windows 11, so Windows 10 users keep a yellow outline around everything they filter.
Glass mode costs frames on modern titles. Running a current game borderless and compositing a shader pass over it at desktop resolution is not free. Window clone mode is lighter because it can bypass desktop composition, but the overhead is still there, and users pairing it with other overlays report added input delay.
It only ever sees the finished frame. No depth buffer, no access to the game’s internal render resolution, no HDR retrofit. Ambient occlusion shaders, depth-based fog and anything else that needs geometry data cannot work through a capture layer.
Old-style windows slip through. Some legacy rendering windows are not supported by the modern Windows capture API at all, which pushes you back to full desktop mode and whatever is behind the game.
The alternatives
ReShade, best for filters inside modern games
ReShade solves the exact problem ShaderGlass cannot. It installs into the game’s folder and hooks the renderer directly, covering Direct3D 9 through 12, OpenGL and Vulkan, so exclusive fullscreen is a non-issue. Version 6.8.0 landed on 2 August 2026 with parser fixes and additions for add-on developers. The generic depth add-on ships in the standard build and gives shaders access to the depth buffer, though ReShade disables that automatically when it detects network activity so nobody turns a fog shader into a wallhack. The community shader repository includes CRT and scanline effects, and it is where most of the sharpening, tonemapping and film-grain presets people share actually come from.
Where it falls short: you install it per game, and the full add-on build is explicitly not recommended for anything with anti-cheat. The retro shader selection is a fraction of the libretro catalogue, and ReShade does nothing at all for video players, emulator frontends or a pixel-art editor.
Pricing: free, funded by donations.
ShaderGlass vs ReShade: ShaderGlass filters what your monitor shows, ReShade filters what the game draws. If the target is a 2024 title in fullscreen, only one of them can reach it.
Download: reshade.me
Bottom line: pick ReShade for modern single-player games, and keep ShaderGlass for everything that is not a game.
Magpie, best free window overlay
Magpie is the closest architectural match on this list. It is GPLv3, runs on Windows 10 version 1903 and later, and takes a windowed application fullscreen through a shader chain of your choosing. The built-in effect list covers FSR, NVIDIA Image Scaling, Anime4K, xBRZ, RAVU and NNEDI3, plus the CuNNy family that handles text in visual novels better than Anime4K does, and it carries CRT_Easymode and CRT_Geom for the arcade look. Sharpening, debanding, anti-aliasing and colour adjustment sit alongside them, and recent 0.12.x releases added cursor rendering improvements and more RAVU and NNEDI3 variants.
Where it falls short: the effect count is in the dozens, not the hundreds, so the deep CRT presets people install ShaderGlass for are not here. Magpie is an upscaler that also does effects, which means it always wants to scale a window rather than sit transparently over your desktop, and like ShaderGlass it cannot touch exclusive fullscreen.
Pricing: free.
ShaderGlass vs Magpie: same capture-based approach, different priority. Magpie leads with scaling quality, ShaderGlass leads with shader variety.
Download: github.com/Blinue/Magpie · Releases
Bottom line: pick Magpie if the goal is a sharp, well-scaled window and a CRT option is a bonus rather than the point.
RetroArch, best for the shader library at its source
RetroArch is where ShaderGlass’s 1200 shaders came from. Its slang pipeline runs multi-pass presets natively, and crt-royale, the most demanding of them, models aperture grille geometry, phosphor persistence, halation and bloom as separate stages rather than faking them in one pass. Presets attach per core or per game, so a Game Boy core can carry a dot-matrix shader while a Mega Drive core gets a composite filter, and none of it is re-applied after the fact through a capture layer.
Where it falls short: it only applies to content running inside libretro cores. Standalone emulators, PC games, videos and desktop apps are all outside its reach. The shader menus are dense, GLSL and slang presets are not interchangeable, and picking the wrong video driver quietly locks you out of half the library.
Pricing: free.
ShaderGlass vs RetroArch: RetroArch gives you the same shaders one layer lower and one step cleaner, as long as the thing you are filtering runs inside it.
Download: retroarch.com · GitHub
Bottom line: pick RetroArch if retro consoles are the whole use case, and skip it the moment you want filters on anything else.
Lossless Scaling, best for scaling and frame generation
Lossless Scaling takes the same window-capture approach as ShaderGlass and points it at frame rate instead of nostalgia. It costs $6.99 on Steam from developer THS, sits at Very Positive across more than 36,000 reviews, and its LSFG 3.1 engine generates interpolated frames in almost any game on almost any GPU without waiting for a developer to add DLSS or FSR. The scaling side covers the developer’s own LS1 algorithm, FSR, NIS, Anime4K, xBRZ and integer scaling, which makes it a genuinely good fit for a 240p emulator window blown up to 4K.
Where it falls short: there is no CRT shader library. Nothing here reproduces phosphor masks, scanlines or aperture grilles, because that is not what it is for. Frame generation also adds latency and produces artifacts around fast-moving UI elements, and dual-GPU setups get noticeably better results than single-GPU ones.
Pricing: $6.99 one-time on Steam.
ShaderGlass vs Lossless Scaling: same capture plumbing, opposite goals. One makes the picture look older, the other makes it run smoother.
Download: Steam · losslessscaling.com
Bottom line: pick Lossless Scaling if frame rate and sharpness matter more than the retro look, and run it alongside ShaderGlass rather than instead of it.
Special K, best for fixing the frame before you filter it
Special K is a GPLv3 injector with a much wider brief than post-processing. Its HDR retrofit forces an scRGB 16-bit or HDR10 swapchain into Direct3D 11 and 12 games that never shipped HDR, then undoes the game’s own tone mapping with a configurable one of its own. On native D3D11 titles it can remaster 8-bit, 10-bit and 11-bit render passes for a cleaner result, and adaptive tone mapping is available on top. Frame pacing, latency measurement, texture modding and per-game plug-ins fill out the rest, and the project ships updates constantly.
Where it falls short: the learning curve is real, and the global injection service can collide with anti-cheat, Steam overlays and other injectors. It is not a shader gallery. There is no browsable list of CRT presets waiting for you, and getting a specific look out of it means reading the wiki.
Pricing: free.
ShaderGlass vs Special K: ShaderGlass changes how the finished image looks, Special K changes what the game hands the display in the first place.
Download: special-k.info · GitHub
Bottom line: pick Special K when the problem is the game’s output rather than your taste in filters.
NVIDIA app, best zero-install option on GeForce
The NVIDIA app replaced GeForce Experience and kept Freestyle, which applies post-processing filters from a Ctrl+G overlay across a driver-level supported game list of over a thousand titles. Two AI filters carry it beyond the old sharpen-and-saturate set: RTX HDR brings HDR output to games that never shipped it, and RTX Dynamic Vibrance boosts clarity per application without crushing colour the way a flat saturation slider does. Nothing to install per game, nothing to configure in a text file.
Where it falls short: GeForce only, and Radeon owners have no equivalent, since AMD’s Adrenalin offers display colour controls rather than stacked post-processing filters. The filter set is colour, contrast, sharpening and vibrance, so there are no scanlines, no phosphor masks and no pixel-art scalers. Plenty of competitive titles block the overlay outright.
Pricing: free with GeForce hardware.
ShaderGlass vs NVIDIA app: the NVIDIA app is faster to reach and works in fullscreen, but its filters are corrective rather than transformative.
Download: nvidia.com/en-us/software/nvidia-app
Bottom line: pick the NVIDIA app if you want a game to look cleaner in thirty seconds, not older in thirty minutes.
mpv, best for shaders on video
A good share of ShaderGlass installs end up pointed at a video window rather than a game, and mpv does that job properly. It loads GLSL user shaders through --glsl-shaders, which is how Anime4K’s modes A, B and C are meant to run, with A tuned for 1080p sources, B for 720p and C for 480p. Drop the .glsl files into %APPDATA%\mpv\shaders, bind a profile, and the shader runs on decoded frames rather than on a recompressed capture of your screen. Scaler choice, dithering and HDR passthrough are all configurable, and prebuilt configs exist if you would rather not start from an empty mpv.conf.
Where it falls short: video only. It will not filter a game, an emulator or your desktop. Configuration is a text file with no GUI, and mpv’s user-shader hook format is not libretro’s, so a .slangp preset needs porting before it will load.
Pricing: free.
ShaderGlass vs mpv: for anything playing back a video file, mpv applies the shader to the source instead of to a capture of the window showing it.
Bottom line: pick mpv for video, and keep ShaderGlass for the browser tab you cannot pipe through a local player.
How to choose
Pick ReShade if the games you want to filter are modern and run in exclusive fullscreen. That single limitation is the reason most people go looking for a ShaderGlass replacement, and ReShade is the direct answer to it.
Pick Magpie if you liked the ShaderGlass model but want better scaling and a lighter capture path, especially for a small emulator window stretched across a 4K panel. It is free and it will not ask you to touch a game’s install folder.
Pick RetroArch if the retro look is the whole reason you are here. Running crt-royale on the emulator itself beats running it on a screenshot of the emulator, and per-core presets mean you set it up once.
Pick Lossless Scaling if what you actually want is more frames. The $6.99 is the least contentious spend on this list, and it stacks fine with a shader overlay.
Pick Special K if the underlying image is the problem: no HDR, bad frame pacing, wrong colour space. Filters cannot fix a broken swapchain.
Pick the NVIDIA app if you have GeForce hardware and want a fullscreen-safe filter overlay with no install per game.
Pick mpv if the target is video, since a decoded frame is a better place to run a shader than a captured window.
Stay on ShaderGlass if your library is DOSBox, ScummVM, VICE, FS-UAE, Altirra and pixel-art tools. Nothing else here gives you 1200 libretro presets on top of an arbitrary window, and version 1.3 added USB source capture, profile saving, external .slangp imports and clone-mode support under Wine and Proton. For that specific set of software it remains the best tool available, and it costs nothing.
FAQ
Is there a free alternative to ShaderGlass?
Five of the seven here are free: ReShade, Magpie, RetroArch, Special K and mpv. Magpie is the closest free match in how it works, since it also captures a window and runs shader effects over it, including CRT_Geom and CRT_Easymode. Only Lossless Scaling costs money, at $6.99 on Steam.
Does ShaderGlass work in fullscreen games?
Only in borderless fullscreen. Exclusive fullscreen is not supported, because ShaderGlass captures the desktop or a window rather than hooking the game’s renderer. Switch the game to borderless or windowed mode, or use ReShade instead, which injects into the render pipeline and works in exclusive fullscreen.
What is the difference between ShaderGlass and ReShade?
ShaderGlass runs after the frame reaches your screen, so it works on any window including emulators, video players and desktop apps, but it cannot see depth data or reach exclusive fullscreen. ReShade runs inside the game’s renderer, which gives it depth buffer access and fullscreen support but limits it to one game at a time.
Can I use RetroArch shaders outside RetroArch?
Yes. ShaderGlass bundles the libretro library and accepts external .slangp and .slang files, and Magpie ports several of the same CRT effects. Formats do not travel everywhere, though: mpv uses its own GLSL user-shader hooks, so a libretro preset has to be rewritten before mpv will load it.
Which ShaderGlass alternative adds CRT scanlines to modern PC games?
ReShade, since it is the only one on this list that reaches a modern game running in exclusive fullscreen. The community repository includes CRT and scanline shaders, and you can add more. The look will not match a full crt-royale pass in RetroArch, which runs multiple shader passes on a low-resolution source the way the effect was designed for.
