The 10-inch ULW10 Traveller and its 4:3 CRT-inspired cousins keep going viral for a reason. A small, boxy panel next to a mini-PC looks like the childhood setup a lot of us wanted back. But the monitor alone does not fix the picture. Plug in a modern emulator on default settings and PS1, N64, SNES and NES games still render at the wrong aspect ratio, upscaled with flat pixels that never sat on a real Trinitron.
The best apps for 4:3 CRT retro emulation do three things well. They lock output to native 4:3, they scale with integer math so pixels stay clean, and they ship (or accept) shaders that reintroduce scanlines, mask, glow and phosphor bleed. These seven apps cover NES through PS2 on Windows, macOS and Linux, and they leave the shader stack to you.
What to look for in a CRT emulation app
A short checklist keeps the shortlist honest.
- Shader library. CRT-Royale, crt-guest-advanced (and its HD variant), crt-lottes and Sony Megatron are the ones that hold up on modern panels.
- Forced aspect ratio. The app should let you lock 4:3 per-core or per-game, not just system-wide.
- Integer scaling. Non-integer scales blur pixel art before the shader ever runs.
- BIOS handling. PS1, PS2 and Saturn need real BIOS files; the app should surface missing files clearly instead of silently falling back.
- RetroAchievements support. Optional, but a nice tie-in with the RetroAchievements service for people who want cheevos on cartridges.
- Active development. Emulator accuracy still moves. A dead project on a fast-moving system (looking at you, PS2) is a red flag.
Quick comparison
| App | Best for | Cores or systems | Free? | Shaders | Rating |
|---|---|---|---|---|---|
| RetroArch | All-in-one shader hub | 100+ libretro cores | Yes | Huge built-in library | 5/5 |
| Mesen | NES, SNES, GB, PC Engine accuracy | NES, SNES, GB, PCE | Yes | Built-in, per-system | 5/5 |
| Duckstation | PlayStation 1 | PS1 | Yes | Slim CRT set | 5/5 |
| PCSX2 | PlayStation 2 | PS2 | Yes | Post-process shaders | 4.5/5 |
| Dolphin | GameCube and Wii | GC, Wii | Yes | Rich shader pipeline | 4.5/5 |
| BizHawk | TAS authoring and accuracy | NES, SNES, GB, GBA, N64, Genesis, PSX | Yes | Basic | 4.5/5 |
| ShaderGlass | System-wide shader overlay | Any window | Yes | Ports of libretro presets | 4.5/5 |
The seven apps
1. RetroArch
RetroArch is the shader hub for retro emulation on PC. It runs more than a hundred libretro cores under one roof and ships with the CRT presets most people actually want, including CRT-Royale, crt-guest-advanced-hd and Sony Megatron. Aspect ratio, integer scale and shader can all be locked per-core, so a 4:3 override on the NES core does not follow you into a widescreen PS2 preset.
Where it falls short: the menu is famously dense, and first-run setup takes an hour before it feels dialled in.
Pricing: Free.
Platforms: Windows, macOS, Linux.
Download: Steam or retroarch.com.
Bottom line: if you only install one thing on the mini-PC behind your 4:3 panel, install this.
2. Mesen
Mesen is the go-to for NES, SNES, Game Boy and PC Engine when you want per-scanline accuracy. Its built-in HD packs and shader stack are cleaner than the RetroArch equivalents for those systems, and the debugger is a genuinely useful tool for anyone poking at ROM hacks or homebrew.
Where it falls short: scope is deliberately narrow. Anything past 16-bit belongs in a different app.
Pricing: Free.
Platforms: Windows, macOS, Linux.
Download: mesen.ca.
Bottom line: the sharpest option for the systems it covers, and it keeps its 4:3 output honest.
3. Duckstation
Duckstation has become the default PlayStation 1 emulator for a reason. PGXP kills the geometry wobble that made original hardware look drunk, per-game profiles let you lock 4:3 on a title that would otherwise stretch, and the built-in CRT shader set is small but tuned for PS1 material.
Where it falls short: the standalone is Windows and Linux first; the macOS build lags a little behind.
Pricing: Free.
Platforms: Windows, macOS, Linux.
Download: duckstation.org.
Bottom line: the cleanest PS1 picture on a 4:3 panel, with none of the setup pain of the older PS1 emulators.
4. PCSX2
PCSX2 is the PS2 emulator that finally feels stable across the library. Widescreen patches exist, but on a 4:3 CRT-inspired display the point is to leave them off. Native 4:3 render combined with a CRT post-process shader is what makes Ratchet, Jak and the Sly games look like they did on a Sunday afternoon in 2004.
Where it falls short: PS2 remains the heaviest system in this list. A weak CPU shows.
Pricing: Free.
Platforms: Windows, macOS, Linux.
Download: pcsx2.net.
Bottom line: the PS2 pick, and the one system where you actively want to skip the widescreen hack.
5. Dolphin
Dolphin covers GameCube and Wii, and it handles native 4:3 well for the GameCube library and Wii titles that predate the widescreen wave. The shader pipeline is rich enough to run the same crt-guest and Royale presets people use elsewhere, and Metroid Prime on a small 4:3 panel is worth the setup on its own.
Where it falls short: later Wii games were built for 16:9 and look wrong stretched into 4:3. Pick per title.
Pricing: Free.
Platforms: Windows, macOS, Linux.
Download: dolphin-emu.org.
Bottom line: the GameCube half of the library is the reason to install it, and it plays nicely with CRT shaders.
6. BizHawk
BizHawk is the TAS-oriented emulator, which sounds niche until you notice how much of its polish comes from that lineage. Frame-accurate cores for NES, SNES, GB, GBA, N64, Genesis and PSX, deterministic saves, and a rewind that just works. Shader support is basic compared to RetroArch, but for authoring or replaying tool-assisted runs on a CRT panel it is the safest pick.
Where it falls short: Windows first. The Linux build works but is a step behind.
Pricing: Free.
Platforms: Windows, Linux.
Download: tasvideos.org/BizHawk.
Bottom line: the TAS-author and preservationist choice, with enough accuracy to justify a spot next to RetroArch.
7. ShaderGlass
ShaderGlass is the sleeper hit for a 4:3 retro setup. It sits as a transparent overlay window on top of any emulator, DOSBox, ScummVM, or even a modern game, and applies the libretro CRT presets people already know. If your favourite emulator has weak shader support, ShaderGlass fills the gap without touching its render pipeline.
Where it falls short: Windows only. The overlay approach also confuses some capture software.
Pricing: Free.
Platforms: Windows.
Download: github.com/mausimus/ShaderGlass.
Bottom line: the way to get CRT-Royale on top of an app that would otherwise never support it.
How to pick the right one
Match the app to how you actually play. Single-system purists on NES, SNES or PC Engine should install Mesen and be done. Everything-in-one players who want one launcher and one shader stack across every system belong on RetroArch, and that is most people. TAS authors and preservationists want BizHawk for the frame-accurate cores and deterministic saves, even if they run RetroArch alongside for casual sessions.
PlayStation 1 fans get more out of standalone Duckstation than the RetroArch core, mostly because of per-game profiles and PGXP tuning. PS2 fans want PCSX2 standalone for the same reason. Non-emulator users, or anyone using DOSBox, ScummVM or an old Windows-native port, should pair whatever launcher they already use with ShaderGlass on top. And N64 devotees are the group most likely to install both RetroArch (for shader work) and a standalone (for compatibility on the trickier late-generation titles).
FAQ
What is the best 4:3 CRT shader?
CRT-Royale is the community reference for a slot-mask trinitron look. crt-guest-advanced (and its HD variant) is faster and easier to tune. Sony Megatron is the one to try on HDR displays. All three ship in RetroArch and are ported to ShaderGlass.
Do you need a 4:3 monitor to use CRT shaders?
No. CRT shaders work on any modern display, and they look great on a 16:9 panel with a 4:3 letterbox. A physical 4:3 panel (or a 4:3-shaped monitor like the ULW10) just removes the letterbox and gets the geometry closer to what the games were designed against.
Is RetroArch better than standalone emulators?
For shader work and single-launcher convenience, yes. For per-system polish, no. Mesen, Duckstation and PCSX2 standalones each beat their RetroArch cores in specific ways. A common setup is RetroArch as the everyday launcher plus one or two standalones for the systems you play most.
Which emulator has the best PS1 CRT look?
Duckstation standalone with a light CRT preset and PGXP enabled. The per-game aspect ratio lock is the piece that RetroArch’s PS1 cores make harder to reach.
Are these apps legal?
The emulators themselves are legal open-source software. BIOS files and game ROMs are a separate question and depend on where you live and how you obtained them. None of the apps above ship BIOS or game files.
Do CRT shaders work over Steam or GOG games?
RetroArch does not touch native PC games. ShaderGlass does, as an overlay. It is the cleanest way to put a CRT shader over a modern game running on the same 4:3 panel.
