# Understanding the Types of Lag on Your Minecraft Server (TPS, Network, Client) (/docs/minecraft/types-of-server-lag)



"Lag" on Minecraft can mean three completely different things, each with a completely different fix. Knowing which type you have saves hours of pointless troubleshooting.

| Type                   | Where it happens          | Affects     | How to spot it                                  |
| ---------------------- | ------------------------- | ----------- | ----------------------------------------------- |
| **Server lag (TPS)**   | The server                | Everyone    | All players see delay at the same time          |
| **Network lag (ping)** | Between player and server | Individuals | Only some players lag — others are fine         |
| **Client lag (FPS)**   | Player's PC               | Individuals | Choppy visuals but server actions work normally |

Server Lag (Low TPS) [#server-lag-low-tps]

What it is [#what-it-is]

The server can't process all the work that fits in a 20-tick-per-second budget. Each tick should take 50 ms or less; when it takes longer, TPS drops below 20 and the world slows down.

Symptoms [#symptoms]

* Block placing/breaking has a delay
* Mobs walk in slow motion
* Chat messages take seconds to appear
* Item drops freeze in place
* **All players experience it at the same time**

TPS Reference [#tps-reference]

| TPS   | MSPT   | Status                     | Players notice?        |
| ----- | ------ | -------------------------- | ---------------------- |
| 20.0  | \<50   | Perfect                    | No                     |
| 19–20 | 50–55  | Good                       | No                     |
| 17–19 | 55–65  | OK                         | Barely                 |
| 14–17 | 65–80  | Noticeable lag             | Yes                    |
| 10–14 | 80–100 | Significant lag            | Yes — complaints start |
| \<10  | >100   | Severe — nearly unplayable | Yes — players leave    |

Common Causes [#common-causes]

| Cause                                  | How common  |
| -------------------------------------- | ----------- |
| Too many entities (mob farms)          | Very common |
| Chunk generation from exploration      | Very common |
| High view-distance/simulation-distance | Very common |
| Heavy redstone                         | Common      |
| Bad plugin or mod                      | Common      |
| Insufficient RAM (GC pauses)           | Common      |
| World corruption                       | Occasional  |

Diagnosis [#diagnosis]

1. Run `/spark tps` to confirm TPS is low
2. Run `/spark profiler start`, wait 2–5 minutes, then `/spark profiler stop`
3. Read the flame graph — the widest bars are your culprit
4. See [Setup Spark](/docs/minecraft/setup-spark) for details

Fix [#fix]

* [Optimize Server](/docs/minecraft/optimize-server) — full performance guide
* [JVM Flags](/docs/minecraft/jvm-flags) — Aikar's flags
* [Render Distance](/docs/minecraft/render-distance) — biggest single lever
* [Pre-generate Chunks](/docs/minecraft/pregenerate-chunks) — eliminate exploration lag
* [Server Tick Loop](/docs/minecraft/fix-server-tick-loop) — for "Can't keep up"

Network Lag (High Ping) [#network-lag-high-ping]

What it is [#what-it-is-1]

Slow or unstable connection between an individual player and the server. The server is fine — the player's packets are taking too long to arrive.

Symptoms [#symptoms-1]

* Delayed actions
* Rubber-banding back to a previous position
* Block breaks reset and have to be redone
* **Only affects specific players** — others connect fine

Common Causes [#common-causes-1]

| Cause                                        | Who it affects           |
| -------------------------------------------- | ------------------------ |
| Player far from the server geographically    | One player or one region |
| Player on Wi-Fi instead of Ethernet          | One player               |
| Player's ISP routing through congested peers | One player               |
| Player on mobile data / hotspot              | One player               |
| Server bandwidth saturation                  | Everyone (rare)          |
| Datacenter network issue                     | Everyone (rare)          |

Diagnosis [#diagnosis-1]

In-game, run:

```
/list
```

Or with Spark:

```
/spark ping
```

This shows ping per player. **If only some players have high ping, the issue is on their end.** If everyone has high ping, the server's network is the problem.

Fix [#fix-1]

* **Player side**: switch to Ethernet, change DNS to 1.1.1.1, contact ISP
* **Server side**: usually nothing to do unless it's a datacenter issue
* **Datacenter side**: choose a host location closer to your community

Client Lag (Low FPS) [#client-lag-low-fps]

What it is [#what-it-is-2]

The player's computer can't render the game fast enough. **This is not a server problem at all.**

Symptoms [#symptoms-2]

* Choppy visuals, stuttering
* Game feels slow
* Mouse input feels delayed
* Server actions (block placing, mob behavior) are normal — only the rendering is choppy
* **Only affects one player**

Diagnosis [#diagnosis-2]

Have the player press **F3** in Minecraft. The top-right shows their FPS:

| FPS   | Status         |
| ----- | -------------- |
| 60+   | Smooth         |
| 30–60 | OK             |
| 15–30 | Noticeable lag |
| \<15  | Severe         |

If their FPS is low but the server's `/spark tps` is 20.0, it's a client issue.

Fix [#fix-2]

These are all **client-side**, not server changes:

* Lower client render distance (Settings → Video Settings)
* Lower graphics quality
* Install [Sodium](https://modrinth.com/mod/sodium) (Fabric) or [Embeddium](https://modrinth.com/mod/embeddium) (Forge) for better FPS
* Disable shaders
* Allocate more RAM to the Minecraft launcher
* Update GPU drivers
* Close other apps

Quick Diagnosis Flowchart [#quick-diagnosis-flowchart]

```
Players reporting lag.
        │
        ▼
Does EVERYONE lag at the same time?
   │              │
  YES             NO
   │              │
   ▼              ▼
Server lag    Does ONE player lag?
(check TPS)        │              │
                  YES             NO
                   │              │
                   ▼              ▼
            Network or client    Many players lag
            (check their FPS     (server lag — check TPS)
             and ping)
```

Common Mistakes [#common-mistakes]

| Mistake                                     | Fix                                         |
| ------------------------------------------- | ------------------------------------------- |
| Treating client FPS lag as a server issue   | Have the player check F3 first              |
| Adding RAM to fix network lag               | RAM doesn't fix ping — it's a network issue |
| Ignoring "Can't keep up" warnings           | They mean TPS is dropping — investigate     |
| Assuming all lag is the same                | Diagnose first, fix second                  |
| Lowering view-distance for one laggy player | Won't help — that's a client issue          |

Related Guides [#related-guides]

* [Optimize Server](/docs/minecraft/optimize-server)
* [Setup Spark](/docs/minecraft/setup-spark)
* [Server Tick Loop](/docs/minecraft/fix-server-tick-loop)
* [Render Distance](/docs/minecraft/render-distance)
* [Pre-Generate Chunks](/docs/minecraft/pregenerate-chunks)
* [JVM Flags](/docs/minecraft/jvm-flags)
* [How Much RAM](/docs/minecraft/how-much-ram)