Why Lethal Company Lag Ruins Co-op Horror
In Lethal Company, lag isn’t just annoying—it’s deadly. When the host has network issues, monsters teleport, doors desync, and players rubber-band into deadly traps while their teammates see them standing safely elsewhere. Since Lethal Company uses peer-to-peer hosting through Unity’s Netcode for GameObjects, every player’s experience depends entirely on the host’s PC performance and internet connection.
How to Check If You Have a Lag Problem
Lethal Company doesn’t include built-in network statistics, so identifying lag requires external monitoring. The host should open Task Manager during gameplay and monitor LethalCompany.exe CPU usage—consistent spikes above 80% indicate processing bottlenecks that cause lag for all players.
For network monitoring, download NetLimiter or Resource Monitor. During gameplay, check the host’s upload bandwidth usage. Lethal Company uses approximately 50-100 KB/s upload per connected player. With 4 players total, the host should see 150-300 KB/s upload usage. If upload usage fluctuates wildly or hits your connection’s limit, network lag follows.
Players can test their connection to the host using Windows Command Prompt. Type ping [host’s IP address] -t and run it during gameplay. Consistent ping below 50ms indicates good connectivity. Ping spikes above 150ms or packet loss percentages above 1% cause noticeable desync issues.
To distinguish between FPS lag and network lag: FPS lag affects only your screen (stuttering, low framerate) while network lag affects player positions, item interactions, and monster behavior for everyone. If other players see you teleporting or interacting with objects incorrectly, you’re experiencing network issues.
Steam’s in-game overlay shows FPS in the top-left corner when enabled. Press Shift+Tab, go to Settings > In-Game, and enable “In-game FPS counter.” Maintain 60+ FPS consistently. Below 30 FPS indicates performance issues that will impact hosting quality.
DNS Server Optimization
Change to Gaming-Optimized DNS Servers
Your ISP’s default DNS servers add 10-30ms latency to initial connections. Switching to Cloudflare’s 1.1.1.1 and 1.0.0.1 reduces this overhead significantly. Open Windows Settings > Network & Internet > Ethernet (or Wi-Fi) > Change adapter options. Right-click your connection, select Properties, double-click “Internet Protocol Version 4 (TCP/IPv4).”
Select “Use the following DNS server addresses” and enter 1.1.1.1 as primary, 1.0.0.1 as secondary. For gaming-specific DNS, use Quad9’s 9.9.9.9 and 149.112.112.112, which prioritize low latency over content filtering.
After changing DNS, open Command Prompt as Administrator and run ipconfig /flushdns followed by ipconfig /renew. This clears cached DNS entries and forces immediate adoption of new servers.
Set Custom DNS on Router Level
Router-level DNS changes affect all devices automatically. Access your router’s admin panel (typically 192.168.1.1 or 192.168.0.1 in a web browser). Navigate to Network Settings or WAN Settings. Find DNS Server settings and replace your ISP’s addresses with 1.1.1.1 and 1.0.0.1.
For routers supporting DNS over HTTPS, enable it with Cloudflare’s endpoint: https://cloudflare-dns.com/dns-query. This prevents ISP throttling of DNS requests, which some providers implement during peak hours.
Port Forwarding and Network Configuration
Forward Lethal Company’s Required Ports
While Steam’s networking relay works for most connections, direct P2P through port forwarding eliminates relay server latency. The host needs TCP and UDP port 7777 forwarded to their PC’s local IP address. Find your local IP by opening Command Prompt and typing ipconfig—look for “IPv4 Address” under your active network adapter.
Access your router’s admin panel and navigate to Port Forwarding, Virtual Servers, or Gaming sections. Create two rules: one for TCP port 7777, one for UDP port 7777, both pointing to the host’s local IP address. Enable UPnP (Universal Plug and Play) in your router settings to allow automatic port management.
Related: Game Lag Fix: Every Cause of In-Game Lag Solved for PC and Console
Additionally, forward Steam’s P2P ports for improved connectivity: UDP 27000-27100 and TCP 27015-27030. These handle Steam’s networking layer beneath Lethal Company’s game traffic.
Configure Windows Firewall Exceptions
Windows Firewall blocks incoming connections by default, even with ports forwarded at the router level. Open Windows Security > Firewall & network protection > Allow an app through firewall. Click “Change Settings,” then “Allow another app.” Browse to Lethal Company’s installation folder (typically C:\Program Files (x86)\Steam\steamapps\common\Lethal Company) and select LethalCompany.exe.
Enable both Private and Public network checkboxes for Lethal Company. Do the same for Steam.exe, located in C:\Program Files (x86)\Steam. This prevents Windows from blocking legitimate game traffic.
Set Router QoS Gaming Priority
Quality of Service (QoS) settings prioritize gaming traffic over bandwidth-heavy applications like streaming or downloads. In your router’s QoS section, enable Gaming Mode or Gaming Accelerator if available. Set the host’s PC as highest priority device.
For manual QoS configuration, allocate 80% of upload bandwidth to gaming traffic. If you have 10 Mbps upload, reserve 8 Mbps for gaming. Set Lethal Company’s port 7777 as highest priority, with low latency queue enabled.
Optimize Network Connection Type
Switch from Wi-Fi to Ethernet
Wi-Fi adds 5-15ms latency and introduces packet loss, especially problematic for hosting. Ethernet connections provide stable, low-latency networking essential for smooth P2P hosting. Use Cat6 or Cat5e cables for gigabit speeds—Cat5 limits bandwidth to 100 Mbps.
If Ethernet isn’t feasible, optimize Wi-Fi by connecting to 5GHz networks instead of 2.4GHz. The 5GHz band offers lower latency and less congestion. Change your router’s channel to 36, 40, 44, or 48 for optimal performance—these channels avoid interference from microwaves and Bluetooth devices.
Test and Optimize MTU Size
Maximum Transmission Unit (MTU) size affects packet efficiency. Windows defaults to 1500 bytes, but some connections perform better with smaller values. Test optimal MTU using Command Prompt: ping google.com -f -l 1472. If this succeeds, try ping google.com -f -l 1473. Continue increasing until packets fragment, then use the largest successful size plus 28 bytes.
Set custom MTU through Network Adapter Properties. Open Device Manager > Network adapters, right-click your Ethernet adapter, select Properties > Advanced. Find “Jumbo Packet” or “MTU Size” and set the value you determined through testing.
In-Game Settings Optimization
Graphics Settings for Stable Hosting
Open Lethal Company’s Settings > Video. Set Quality to Medium—High and Ultra quality increase CPU usage significantly, causing lag spikes when hosting. The Unity engine’s rendering pipeline becomes CPU-bound at higher settings, competing with networking processes.
Set Resolution to 1920×1080 if hosting on higher resolution monitors. 1440p and 4K increase GPU load, but more importantly, they increase VRAM usage. When VRAM fills up, the system uses regular RAM, causing stuttering that affects all players.
Disable V-Sync completely. V-Sync introduces input lag and frame timing inconsistencies that affect server tick rate stability. Instead, use your graphics card’s control panel to set a frame rate cap of 120 FPS if your monitor supports it, or 60 FPS for 60Hz displays.
Advanced Graphics Tweaks
Set Fullscreen Mode to Exclusive Fullscreen, not Borderless Windowed. Exclusive mode gives Lethal Company direct GPU access, reducing frame timing variance. Borderless mode forces the Windows compositor to manage frames, adding latency.
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In the game’s graphics settings, set Shadow Quality to Low and Texture Quality to Medium. Shadows are CPU-intensive in Unity, and texture streaming from disk can cause hitches when loading new areas on moons like Rend and Titan.
Disable Motion Blur and Depth of Field if these options appear in graphics settings. These post-processing effects consume GPU resources without improving gameplay—in horror games, they can actually hinder monster spotting.
Audio Settings for Reduced CPU Load
Lethal Company’s 3D audio processing affects CPU usage, especially with multiple players talking simultaneously. In Settings > Audio, set Master Volume and Voice Chat Volume to comfortable levels, but avoid maximum settings which can cause audio processing spikes.
If using external voice chat like Discord, disable Lethal Company’s built-in voice chat entirely. This reduces CPU overhead and eliminates potential audio conflicts that cause stuttering.
System-Level Optimization
Graphics Driver Updates and Settings
Download the latest graphics drivers directly from NVIDIA or AMD websites, not through Windows Update. For NVIDIA cards, open NVIDIA Control Panel > Manage 3D Settings > Program Settings. Add LethalCompany.exe and configure these settings: Power Management Mode to Prefer Maximum Performance, Texture Filtering – Quality to High Performance, and Threaded Optimization to On.
For AMD cards, open Radeon Software > Gaming > Global Settings. Enable Radeon Anti-Lag and Radeon Boost. Set Texture Filtering Quality to Performance and Tessellation Mode to Override application settings with Maximum Tessellation Level at 16x.
Windows Game Mode and Priority Settings
Enable Windows Game Mode through Settings > Gaming > Game Mode. This prioritizes CPU and GPU resources for gaming applications and reduces background task interference. Additionally, enable Hardware-accelerated GPU scheduling in Settings > System > Display > Graphics settings for supported GPUs.
Set Lethal Company’s process priority to High while hosting. Open Task Manager during gameplay, find LethalCompany.exe under Processes, right-click and select “Go to details.” Right-click the process in the Details tab, hover over “Set priority,” and select High. This ensures the game gets CPU priority over background applications.
Related: GTA Online Lag Fix: How to Stop Stuttering in Public Lobbies
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Power Plan Optimization
Windows’ default “Balanced” power plan reduces CPU performance during low usage periods, causing lag spikes when demand increases suddenly. Open Control Panel > Power Options and select High Performance. If this option isn’t visible, open Command Prompt as Administrator and run powercfg -duplicatescheme 8c5e7fda-e8bf-4a96-9a85-a6e23a8c635c.
For modern CPUs, create a custom power plan by clicking “Create a power plan” and selecting “High performance” as the base. Set Minimum processor state to 100% and Maximum processor state to 100%. This prevents CPU downclocking during gameplay.
Disable Background Applications
Close unnecessary programs before hosting, particularly bandwidth-intensive applications. Windows built-in apps that commonly cause issues include Windows Update (pause updates during gaming sessions), OneDrive sync, and Windows Defender full scans. Open Task Manager > Startup and disable non-essential programs from launching automatically.
Disable Xbox Game Bar notifications and recording features through Settings > Gaming > Xbox Game Bar. Turn off background app permissions for apps you don’t need in Settings > Privacy > Background apps. Focus particularly on social media apps, news applications, and email clients that frequently sync data.
Advanced Configuration
Unity Engine Launch Options
Add launch options to Lethal Company through Steam’s Library. Right-click Lethal Company, select Properties, and add these launch parameters: -high -threads [number of CPU cores] -malloc=system -force-d3d11. Replace [number of CPU cores] with your CPU’s thread count—for example, an 8-core/16-thread CPU would use -threads 16.
Additional Unity optimization parameters include -nolog to disable debug logging (reduces disk I/O), and -batchmode for dedicated server scenarios. For systems with 32GB+ RAM, add -heapsize 4194304 to allocate 4GB of RAM specifically for Unity’s heap management.
Windows Registry Network Tweaks
Open Registry Editor (regedit) as Administrator and navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters. Create or modify these DWORD values: TcpAckFrequency set to 1, TCPNoDelay set to 1, and TcpDelAckTicks set to 0. These settings reduce TCP acknowledgment delays for gaming traffic.
Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Multimedia\SystemProfile and set SystemResponsiveness to 10 (default is 20). This allocates more CPU time to foreground applications like games.
Memory and Storage Optimization
Lethal Company benefits significantly from SSD storage, not just for faster loading but for reduced hitching when streaming assets. If using a traditional hard drive, defragment it regularly using Windows’ built-in tool or third-party utilities like Defraggler.
For systems with 16GB+ RAM, disable the page file on your primary drive if Lethal Company is installed there. This prevents disk thrashing during memory allocation spikes. Open System Properties > Advanced > Performance Settings > Advanced > Virtual Memory, and set “No paging file” for the SSD containing Lethal Company.
Enable Memory Compression through PowerShell (Run as Administrator): Enable-MMAgent -MemoryCompression. This reduces RAM usage by compressing inactive memory pages, leaving more available for active game processes.
Mod-Specific Lag Solutions
BepInEx and MoreCompany Optimization
Popular mods like MoreCompany (which increases player count to 8+) significantly increase network load for hosts. If hosting modded lobbies, ensure your upload bandwidth can handle the additional players—each extra player requires approximately 50 KB/s additional upload bandwidth.
Configure BepInEx for performance by editing BepInEx\config\BepInEx.cfg in Lethal Company’s installation folder. Set HideManagerGameObject = true to reduce Unity overhead, and UnityLogListening = false to disable debug message processing.
For MoreCompany specifically, monitor your system’s RAM usage during 8+ player sessions. The mod increases memory usage exponentially with player count. Consider reducing graphics quality to Medium or Low when hosting large modded lobbies to compensate for additional CPU and memory overhead.
Identifying Problematic Mods
Some community mods cause frame drops or network stuttering through inefficient code. Remove mods one at a time to identify problematic ones, starting with UI enhancement mods and cosmetic modifications, which often run continuous background processes.
Check BepInEx logs for errors or warnings by reviewing BepInEx\LogOutput.log after gameplay sessions. Frequent NullReferenceException or networking timeout errors indicate specific mods causing issues. Replace these with lightweight alternatives or remove them entirely for stable hosting.
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Frequently Asked Questions
Why do all players lag when I host but not when others host?
Lethal Company uses peer-to-peer networking where the host’s PC performance and internet connection affects everyone. Your upload bandwidth might be insufficient—you need at least 2-3 Mbps upload for stable 4-player hosting. Check your upload speed at speedtest.net and ensure no other devices or applications are consuming bandwidth during gameplay. Additionally, your CPU might be bottlenecking while processing both hosting duties and rendering graphics simultaneously.
What upload speed do I need to host Lethal Company smoothly?
For 4-player vanilla lobbies, maintain at least 2 Mbps upload bandwidth with stable latency below 50ms to other players. Modded lobbies with 8+ players require 5+ Mbps upload minimum. Test your actual upload performance during peak internet usage hours—many ISPs advertise higher speeds than they deliver consistently. Use fast.com or speedtest.net to verify your connection meets these requirements before attempting to host.
How do I fix lag spikes that happen when monsters spawn indoors?
Indoor enemy spawning causes temporary lag spikes due to Unity’s asset loading system. Install Lethal Company on an SSD rather than traditional hard drive to reduce asset streaming delays. Lower graphics quality to Medium, set texture quality to Low, and ensure you have 16GB+ RAM to keep monster assets cached in memory. Close all unnecessary background applications before hosting to free up system resources for asset loading.
Should I use wired or wireless internet for hosting Lethal Company?
Always use wired Ethernet when hosting—Wi-Fi introduces 5-15ms additional latency and packet loss that affects all connected players. If Ethernet isn’t possible, connect to your router’s 5GHz band instead of 2.4GHz, position yourself within 15 feet of the router, and ensure no walls or electronic devices interfere with the signal. Even high-quality Wi-Fi cannot match Ethernet’s consistency for hosting duties.
Why does my game lag more on certain moons like Rend and Titan?
Rend and Titan contain more complex geometry, lighting effects, and weather systems that increase CPU and GPU load significantly. These moons also feature larger indoor facilities with more potential monster spawn points, requiring additional memory for asset management. When hosting on challenging moons, reduce graphics quality to Medium, cap your FPS to 60 to prevent CPU overload, and ensure your system has adequate cooling to prevent thermal throttling during extended sessions.