League of Legends FPS Drops: Causes, Checks and Fixes (2026)

If you have spent any time on Summoner’s Rift recently, you know that a split-second stutter can mean the difference between securing a Baron steal and a gray screen. Unlike modern, GPU-bound cinematic titles, League of Legends runs on a highly customized, proprietary engine that dates back to the game’s inception. While Riot Games has modernized it over the years, the engine remains intensely CPU-bound, relying heavily on single-thread performance and rapid memory allocation.

When you experience frame rate drops in League, it rarely looks like a steady, low frame rate. Instead, it typically manifests as violent micro-stutters during chaotic teamfights—such as when ten champions dump their particle-heavy ultimate abilities at once—or a gradual, compounding degradation of performance as a match stretches past the 30-minute mark. This behavior points to very specific bottlenecks: draw-call limitations, UI rendering overhead, conflicts with Riot Vanguard (the kernel-level anti-cheat), or corrupted local configuration files. This guide details the most effective League of Legends FPS drops fix strategies, moving from simple, non-invasive adjustments to deep system reconfigurations.

Likely Causes

Before editing system files, it helps to understand why the engine is struggling. The table below outlines the primary culprits behind erratic frame rates on the Rift, how to verify them, and the difficulty of their respective fixes.

Fix 1: Reset League Config and Persisted Settings

League of Legends saves your local video, interface, and gameplay settings in a file called game.cfg. Over years of patches, or when syncing with Riot’s cloud servers, this file can accumulate deprecated commands that cause the engine to misinterpret rendering instructions, leading to sudden frame drops.

How to check

Launch a custom game alone. If your FPS remains unstable even when there are no other players, minions, or spells on the screen, your local configuration files may be bloated or corrupted.

What to do

1. Open the Riot Client and log in to your account.
2. Navigate to your main League of Legends installation directory (typically C:\Riot Games\League of Legends\).
3. Open the Config folder.
4. Locate game.cfg and PersistedSettings.json. Right-click and delete both files.
5. Launch a custom game. The game client will automatically generate fresh, clean versions of these files with default parameters optimized for your current hardware.

How to undo it

If you wish to restore your custom keybinds and video settings instantly, retrieve the deleted game.cfg and PersistedSettings.json files from your Windows Recycle Bin and paste them back into the Config folder, overwriting the newly generated ones.

Fix 2: Configure the Riot Client to Close During Gameplay

The Riot Client runs several chromium-based web helper processes in the background. As we move further into 2026, these background web assets have become increasingly resource-heavy, occasionally consuming up to 10% of your CPU’s processing power. Forcing the client to close entirely when the game executable launches frees up crucial CPU cycles for the main game thread.

How to check

While in a match, press Ctrl + Shift + Esc to open the Windows Task Manager. Look for Riot Client (32 bit) or Riot Client UX Helper. If these processes are consuming more than 1-2% of your CPU while you are actively playing, they are actively stealing resources from the game.

What to do

1. Open the Riot Client window (before the game starts).
2. Click on your Profile Icon in the top-right corner and select Settings.
3. Under the Riot Client global settings, look for the option labeled “Close client when game starts”.
4. Change this setting from “Keep client running in background” to “Always”.
5. Click Save. The Riot Client will now automatically terminate its processes the moment your loading screen appears.

How to undo it

Go back into the Riot Client Settings menu, locate the “Close client when game starts” option, and change it back to “Keep client running in background” or “Minimize to system tray.”

Fix 3: Disable In-Game Overlays and Hardware Acceleration

In-game overlays from Discord, Steam, and Nvidia GeForce Experience inject graphics hooks directly into the League of Legends.exe process. Because League’s engine relies on rapid frame presentation, these third-party hooks can disrupt the frame pacing, resulting in noticeable micro-stutters even if your average FPS counter looks high.

How to check

Observe if your frame drops correlate with actions outside the game, such as a friend joining a voice channel, a Discord notification popping up in the corner of your screen, or a achievement toast notification appearing.

What to do

• For Discord: Open Discord, click the gear icon (User Settings) in the bottom left, navigate to the Game Overlay tab under Activity Settings, and toggle off “Enable in-game overlay.” Additionally, go to Advanced settings and turn off Hardware Acceleration.
• For GeForce Experience: Open the GeForce Experience app, click the gear icon, navigate to the General tab, and toggle off the In-Game Overlay switch.

How to undo it

Simply navigate back to the respective settings menus in Discord or GeForce Experience and toggle the overlay options back to “Enabled.”

Fix 4: Disable Windows Fullscreen Optimizations

Windows Fullscreen Optimizations is a built-in feature designed to make games running in borderless windowed mode perform as well as exclusive fullscreen mode. However, for older DirectX 11 engines like League’s, this feature can cause severe presentation lag and random frame drops when panning the camera across the map.

How to check

If your frame rate drops dramatically when panning the camera quickly using the mouse at the edges of your screen, or if you notice a delay when using the Alt + Tab shortcut, Windows is likely struggling to manage its display presentation modes.

What to do

1. Navigate to your League of Legends installation directory, then open the Game folder (usually C:\Riot Games\League of Legends\Game\).
2. Right-click on League of Legends.exe (the application file, not the launcher) and select Properties.
3. Switch to the Compatibility tab.
4. Check the box next to “Disable fullscreen optimizations”.
5. Click Apply, then click OK.

How to undo it

Right-click the League of Legends.exe file again, open Properties, navigate to the Compatibility tab, uncheck “Disable fullscreen optimizations,” and apply the changes.

Fix 5: Add Exclusions for Riot Vanguard in Windows Defender

Riot Vanguard is a kernel-level anti-cheat system that continuously monitors your system’s memory and active drivers. Standard antivirus programs, including Windows Defender, sometimes flag Vanguard’s deep-system scanning as suspicious behavior, leading to a continuous “scanning loop” that spikes your CPU usage during matches.

How to check

Open Windows Task Manager during a match. If you see high CPU spikes from Antimalware Service Executable (Windows Defender) running alongside vgk.sys (Vanguard), your antivirus is actively scanning the anti-cheat while the game is running.

What to do

1. Click the Windows Start button, type Windows Security, and press Enter.
2. Go to Virus & threat protection, then click on Manage settings under “Virus & threat protection settings.”
3. Scroll down to the bottom of the page and click on Add or remove exclusions under the “Exclusions” header.
4. Click Add an exclusion and select Folder.
5. Navigate to and select the entire Riot Vanguard folder (typically located at C:\Program Files\Riot Vanguard\).
6. Repeat the process and add the C:\Riot Games\League of Legends\ folder as well.

How to undo it

Go back to the Exclusions list in Windows Security, click on the added folders (Riot Vanguard and League of Legends), and click the Remove button to restore standard antivirus scanning.

Fix 6: Use Display Driver Uninstaller (DDU) for a Clean GPU Install

Overwriting graphics drivers through standard installers often leaves behind fragmented registry keys and older dll files. These remnants can corrupt your system’s shader cache compilation, causing severe frame drops whenever new visual assets (like champion skins or map environmental effects) load into a match.

How to check

If you experience massive frame drops specifically during the first teamfight of a match, or if your stutters began immediately after updating your graphics drivers, a corrupted driver profile is highly likely.

What to do

1. Download the latest official driver installer for your GPU (Nvidia, AMD, or Intel) and store it on your desktop.
2. Download the latest version of Display Driver Uninstaller (DDU).
3. Boot your PC into Windows Safe Mode (hold Shift while clicking Restart in your Start Menu, then navigate to Troubleshoot > Advanced Options > Startup Settings > Restart, and press 4).
4. Run DDU, select your GPU brand from the dropdown menu, and click “Clean and restart”.
5. Once Windows boots back up normally, run the driver installer you saved to your desktop. Select a “Custom” or “Clean” installation if prompted.

How to undo it

This process cannot be undone via a simple toggle, but running a clean install of your graphics drivers is a standard troubleshooting procedure that leaves your operating system clean and fully updated.

If Nothing Works

If you have implemented all the fixes above and still find your frame rate plummeting on the Rift, the issue may lie in deeper operating system corruption or a faulty hardware state. Your next step should be utilizing the Hextech Repair Tool (HRT), an official diagnostic utility provided by Riot Games. Download and run the tool as an administrator, selecting the “Force Repatch” and “Reinstall Vanguard” options. This will wipe out any hidden system conflicts without requiring a complete manual download of the entire game.

Should the Hextech Repair Tool fail to resolve the issue, gather your diagnostic logs. The HRT will automatically package these logs into a zip file on your desktop. Open a support ticket on the official Riot Games Support website, attach this zip file, and explicitly mention that you have already executed a clean GPU reinstall, cleared your config cache, and configured Vanguard exclusions. This prevents the automated support system from sending you generic troubleshooting steps.

FAQ

Why does my FPS drop only during League teamfights?

Teamfights are incredibly intensive on your CPU’s single-thread performance. The engine must compute hitboxes, spell interactions, cooldown timers, and coordinate rendering instructions for dozens of particle effects simultaneously. If your processor cannot process these instructions fast enough, your graphics card sits idle waiting for instructions, resulting in a sudden drop in frame rate.

Can Riot Vanguard cause FPS drops in League of Legends?

Yes. Because Vanguard operates at the kernel level (Ring 0), it regularly inspects system processes to ensure no malicious software is injecting code into the game. If Vanguard encounters a conflict with a background monitoring tool, RGB controller software, or an aggressive antivirus, it can trigger system latency spikes that manifest as severe stutters in-game.

Should I use DX11 or DX9 legacy mode?

You should use DirectX 11. Riot Games has deprecated support for legacy DirectX 9 rendering pipelines. Attempting to force DX9 mode via configuration file edits can lead to instability, critical client crashes, or severe optimization issues on modern operating systems and graphics cards.

Does capping my FPS help reduce stutters?

Yes, capping your frame rate is highly recommended. If you leave your frame rate uncapped, your CPU and GPU will work at maximum capacity to produce frames you cannot see. When a busy teamfight occurs, your hardware may throttle due to transient power limits or heat, causing a massive drop (e.g., from 300 FPS down to 90 FPS). Capping your FPS to match your monitor’s refresh rate (e.g., 144Hz or 240Hz) ensures consistent frame pacing and keeps your hardware running cool.