Fix Packet Loss in League of Legends

You press Flash, and nothing happens. Your Ezreal Q fires on your screen but the enemy takes no damage. You click to dodge a Blitzcrank hook, but your champion stands still for half a second before lurching forward — straight into it. Then the dreaded gray overlay appears: Attempting to Reconnect.

If any of this sounds familiar, you're probably dealing with packet loss — and it's costing you LP. Packet loss in League of Legends means the data packets carrying your inputs and game state updates are being dropped somewhere between your PC and Riot's servers. Unlike a simple high-ping situation where everything is just delayed, packet loss creates a uniquely frustrating experience: abilities that fire client-side but never register server-side, movement commands that get swallowed entirely, and skillshots that visually connect on your screen but miss according to the server.

The result is a game that feels fundamentally unresponsive and unpredictable. Your champion stutters and hesitates. Auto-attacks cancel themselves. Teamfights become a slideshow where you're mashing buttons and praying something registers. And because League determines hits and misses on the server, lost packets mean the server never received your input at all — it's not just visual, you genuinely didn't act.

The good news: most League packet loss is fixable on your end. This guide covers exactly how to diagnose it, what's causing it, and the specific steps to fix it.

Checking Your Network Stats in League

Before you start troubleshooting, you need to confirm that packet loss is actually your problem — and League gives you a few built-in tools to do that.

The In-Game Overlay (Ctrl+F)

Press Ctrl+F during a game to toggle the performance overlay in the top-right corner. This displays your current FPS and ping (ms) in real time. While this overlay doesn't show packet loss directly, it's your first diagnostic clue. If your ping is stable at, say, 35ms but the game still feels laggy and unresponsive, packet loss is very likely the culprit. If your ping is spiking wildly — jumping from 40ms to 200ms and back — that also points to network instability that typically accompanies packet loss.

Network Indicator Icons

League displays small warning icons on the right side of your screen when it detects network problems. A yellow warning triangle indicates moderate network issues, while a red disconnection icon means you're experiencing severe loss or a full disconnect. If you see these icons flickering on and off during a game, your connection is actively dropping packets.

Using /remake

If you or a teammate disconnects during the first few minutes of a game due to network issues, the team can vote to /remake the match. This ends the game without LP loss for the disconnected player's team (the disconnected player still takes a penalty). It's not a fix, but it's worth knowing about when packet loss hits at the worst possible time.

External Testing

League's built-in tools are limited — they don't show you actual packet loss percentages or where the loss is occurring. For that, you need an external tool. Run a test on PacketProbe before you queue up. It measures packet loss, jitter, and latency simultaneously using unreliable data channels that mimic how real-time game data travels. If PacketProbe shows loss, don't queue ranked.

Why League Uses TCP (And Why It Matters)

Here's something most players don't know: League of Legends uses TCP for its game traffic, which is unusual for a competitive online game. Most multiplayer games — Valorant, Fortnite, Counter-Strike, Apex Legends — use UDP (User Datagram Protocol) because it's faster and doesn't wait for lost packets. UDP just fires data and moves on. If a packet is lost, it's gone.

TCP (Transmission Control Protocol) works differently. It guarantees delivery by requiring the receiving end to acknowledge every packet. If a packet is lost, TCP detects this and retransmits it. Sounds great in theory — no data is ever truly lost. But in practice, this creates a different kind of problem for gaming.

The TCP Stall Problem

When TCP detects a lost packet, it pauses the data stream until that packet is retransmitted and received. This is called a head-of-line blocking stall. Every packet that arrives after the lost one has to wait in a queue until the gap is filled. In a game, this means your entire connection effectively freezes for the duration of the retransmission — typically 50-200ms depending on your ping.

This is why League lag feels different from lag in other games. In a UDP game like Valorant, packet loss causes rubber-banding — your character teleports or snaps to a new position because the server filled in the gaps with prediction. In League, packet loss causes momentary freezes. Everything stops, then suddenly lurches forward as the queued packets all arrive at once. Your champion might stand still for a quarter-second, then suddenly execute three commands in rapid succession.

Why Riot Chose TCP

Riot chose TCP for League because the game is less sensitive to raw latency than an FPS and more sensitive to data integrity. In League, every ability cast, every minion kill, every item purchase needs to be tracked precisely. Dropping that data would cause desyncs that are harder to recover from than a brief stall. It's a reasonable trade-off — but it means that even small amounts of packet loss hit League players harder than you might expect.

What Causes Packet Loss in League

Packet loss can originate anywhere between your PC and Riot's game servers. Here are the most common culprits, roughly ordered from most to least likely.

Wi-Fi

This is the number one cause. Full stop. Wi-Fi is inherently unreliable — it's a shared radio medium subject to interference from walls, other networks, microwaves, Bluetooth devices, and even your neighbor's Wi-Fi. The 2.4GHz band is especially congested in apartment buildings. Even a "good" Wi-Fi connection drops packets regularly; you just don't notice it during web browsing because TCP handles retransmission transparently. In League, those retransmissions manifest as the micro-freezes described above.

ISP Routing to Riot's Servers

Your packets don't travel directly to Riot. They hop through multiple routers owned by your ISP and various transit providers. A single congested or misconfigured router along this path causes packet loss for every game. This is especially common during peak hours (evenings and weekends) when ISP infrastructure is under heavy load. Some ISPs have notoriously bad peering arrangements with Riot's network.

Riot Direct

Riot operates its own network backbone called Riot Direct (shared with Valorant). It's designed to give players dedicated, optimized routing to game servers. However, Riot Direct can only help once your traffic reaches their network — the path from your home to the nearest Riot Direct point of presence is still at the mercy of your ISP. Riot Direct issues are less common but do happen, especially during major events or after infrastructure changes.

The League Client

This one catches people off guard. The League client (the launcher, not the game itself) is built on Chromium and is notorious for memory leaks and high resource usage. It's not uncommon for the client to consume 1-2GB of RAM and significant CPU during a game. On systems with limited resources, this competes with the actual game process and your network stack, potentially causing local packet processing delays that look like network loss.

Other Devices on Your Network

Someone streaming 4K Netflix, a phone backing up to iCloud, Windows Update downloading in the background, a smart home device phoning home — any of these can saturate your upload bandwidth and cause your router to drop gaming packets. Upload bandwidth is typically much lower than download, and League needs reliable upstream connectivity for your inputs to reach the server.

DNS Issues

While DNS doesn't directly affect in-game packet delivery (DNS resolution happens before you connect to the game server), slow or failing DNS can cause issues with the League client's API calls, patch downloads, and login process. It can also cause problems if your system is configured with an unreliable DNS server that occasionally drops requests, leading to intermittent connectivity hiccups.

How to Fix Packet Loss in League

Work through these fixes in order. Start with the easy ones — they solve the problem for the majority of players.

1. Use a Wired Ethernet Connection

If you're on Wi-Fi, stop reading and plug in an Ethernet cable. This single change fixes packet loss for the majority of players. Run a PacketProbe test before and after to see the difference. If you can't run a cable directly, a powerline adapter is a better option than Wi-Fi for gaming, and a MoCA adapter (if you have coax in your walls) is better still.

2. Close the League Client During Games

In the League client settings, enable "Close client during game" under the General tab. This shuts down the resource-heavy client process while you're in a match, freeing up RAM, CPU, and reducing local system load. Also enable "Low Spec Mode" in the client settings — this disables animations and reduces the client's resource footprint when it is running.

3. Run the Hextech Repair Tool

Riot provides the Hextech Repair Tool, a free diagnostic and repair utility. Download it from Riot's support site. It can repair corrupted game files, reset network configurations, flush DNS, and force a clean reinstall of specific components. Run this before you spend time on manual fixes — it automates several of the steps below.

4. Flush Your DNS Cache

Open Command Prompt as administrator and run ipconfig /flushdns. This clears cached DNS entries that might be stale or pointing to suboptimal servers. While you're at it, consider switching to a faster DNS provider. Set your DNS to 1.1.1.1 (Cloudflare) or 8.8.8.8 (Google) instead of your ISP's default DNS servers.

5. Forward the Required Ports

League uses specific network ports that may be partially blocked or throttled by your router's firewall. Log into your router and forward these ports to your PC's local IP address:

Alternatively, if your router supports it, place your PC in the DMZ temporarily to test whether port restrictions are causing the issue. Don't leave DMZ enabled permanently.

6. Disable Full-Screen Optimization

Windows has a "Full-Screen Optimization" feature that can interfere with games. Disable it for both League executables:

  1. Navigate to your League installation folder
  2. Right-click LeagueClient.exe → Properties → Compatibility
  3. Check "Disable full-screen optimizations"
  4. Repeat for League of Legends.exe (in the Game folder)

This prevents Windows from applying its own optimizations that can cause frame pacing issues and interfere with network packet processing.

7. Reduce Network Load

Pause cloud backups, streaming, and large downloads on all devices. If your household has heavy internet usage, enable QoS (Quality of Service) on your router and prioritize gaming traffic. Even a brief bandwidth spike from another device can cause packet loss on your connection if your upload bandwidth is limited.

Riot's Network Tools

Riot provides several official resources for diagnosing network problems. Knowing how to use these can save you hours of blind troubleshooting and give you actionable data if you need to contact support.

Riot's Network Test

Riot hosts diagnostic information and test tools on their support site. You can use these to check your connectivity to specific Riot server regions and identify whether the issue is on your end or theirs.

Running a Traceroute to Riot's Servers

A traceroute shows every router hop between your PC and Riot's game servers, along with the latency at each hop. This is the most powerful diagnostic tool for identifying where packet loss occurs.

Open Command Prompt and run:

tracert 104.160.131.3 (NA server)

Look for:

Submitting a Network Log

If you contact Riot Support about network issues, they'll ask for network logs. The Hextech Repair Tool can generate these automatically. Attach the log file to your support ticket along with the times you experienced issues and your traceroute results. Support agents need this data to escalate routing problems to their network engineering team — vague complaints like "my game is laggy" go nowhere.

Riot Direct Peering

Riot publishes information about their Riot Direct network and its peering arrangements with ISPs. If your ISP has poor peering with Riot, your traffic may take a suboptimal path to their servers. This information can be useful when escalating with your ISP — you can show them the specific peering issue and ask them to investigate their routing to Riot's autonomous system.

When It's Riot's Servers

Sometimes the problem genuinely isn't on your end. Here's how to tell and what to do about it.

Check the Server Status Page

Riot maintains an official server status page for each region. Check this first when you suspect server-side issues. It shows ongoing incidents, scheduled maintenance, and known problems. Riot typically schedules maintenance during off-peak hours (early morning), but emergency maintenance can happen anytime.

Community Reports

The /r/leagueoflegends subreddit and League-focused Discord servers are usually the fastest source of information about widespread server issues. If you see multiple posts about lag or disconnects in your region, it's almost certainly server-side. Twitter/X and Riot's official accounts also post about major outages.

How to Tell If Your ISP Has a Bad Route

There's a specific pattern that points to an ISP routing issue rather than a general server problem: you have consistently high ping or packet loss to one Riot region, but other regions are fine. For example, if you normally get 35ms to NA but suddenly you're getting 90ms with 3% loss, while players in your area report normal connections, the problem is likely your ISP's specific route to Riot's servers.

The traceroute data from the previous section will confirm this. If you see the latency spike occurring at your ISP's routers (not Riot's), contact your ISP with the traceroute evidence. Ask them to check their routing to Riot's network (AS 6507). Some ISPs are responsive to this; others will require persistence.

VPN as a Temporary Workaround

If your ISP has a bad route to Riot's servers, a gaming VPN can sometimes help by routing your traffic through a different path. This isn't a permanent solution — you're adding an extra hop and paying for a service to work around your ISP's infrastructure problem — but it can get you back in the game while the routing issue is being resolved. Not all VPNs help, and some make things worse, so test with PacketProbe both with and without the VPN connected to see if it actually improves your packet loss and latency.

Ultimately, persistent server-side or routing issues require patience and communication. Report the problem to both Riot and your ISP with detailed network data, and check back regularly for resolution. In the meantime, avoid queuing ranked when you know your connection is compromised — your LP and your teammates will thank you.

Test Your Connection for League →