What Is Latency, Why It Matters for Running EAs & How to Lower It

What Is Latency? How Is It Different From Ping?

Latency is the time it takes data to travel from your machine (or the VPS running MT4/MT5) to your broker's server and back again, measured in milliseconds (ms). The lower the number, the better, because it means your buy/sell instructions make the round trip faster.

Ping is really the tool or value used to measure that latency. When we say "ping to the broker is 15 ms," we mean the round-trip latency is about 15 milliseconds. In practice people use "forex latency" and "forex ping" interchangeably.

How Latency Is Measured in ms, and What Counts as Good

Latency is measured by how long a data packet takes to travel round-trip between your machine and the broker's server. A low value means the network path is short and stable. The number depends on physical distance, the quality of the internet route, and how congested the network is at that moment.

There is no single "correct" number that is best for everyone, but generally the closer you get to single or low double-digit ms, the better it suits time-sensitive strategies. Once you reach the hundreds of ms, you tend to notice slower order execution.

• Very low (~1–20 ms) — ideal for scalping/HFT and EAs that need fast fills; usually achieved with a VPS located near the broker's server
• Low to moderate (~20–80 ms) — works well for general EAs and day trading
• High (~100 ms and above) — orders start filling slowly, with more risk of slippage/requotes during volatile market moments

Why Low Latency Matters for Running EAs and Scalping

An EA (Expert Advisor) works by sending automated buy/sell orders based on conditions you set. When a signal meets its conditions, the EA sends the order immediately. If latency is high, the instruction takes longer to travel, and by the time it reaches the broker the price may already have moved, creating a gap between the price you intended and the price you actually get.

For strategies that harvest small gains, such as scalping or news trading, this matters even more, because the profit per trade is thin and a fraction of a second affects entry and exit prices. Low latency helps your orders fill closer to the expected price.

• Faster fills — reduces the time gap between the signal and the actual order being sent
• Less slippage — the price has less time to run away from your intended point
• Fewer requotes — the broker sends fewer new prices because the original price expires less often
• EAs perform closer to backtest — because the timing conditions are close to what was tested

How Latency Relates to Slippage and Requotes

Slippage is the difference between the price you request and the price you actually get. A requote is when the broker rejects the original price and offers a new one to confirm. Both arise from several factors, such as liquidity, volatility, spread, and account type — and latency is one of the factors you can control.

When latency is high, your order takes longer to reach the broker, and during that window the market price may already have changed, so you are more likely to get a different price (slippage) or be offered a new one (requote). Reducing latency therefore reduces the "timing factor" behind these problems, even though it cannot eliminate them 100%.

VPS Server Location vs the Broker's Server

The factor with the biggest impact on latency is the "distance" between the server running your MT4/MT5 and the broker's server. The closer they are on the network, the shorter the data travels and the lower the latency. This is why choosing the "location" of your VPS to match where the broker's server sits is so important.

Before choosing a location, check which region your broker houses its trading servers in (support can usually tell you), then pick a VPS in a nearby region. If you trade with a broker serving Thailand/Asia, using a VPS with a data center in Thailand often gives lower, more stable latency.

A Rough Latency Table by Scenario

This table gives approximate values to illustrate the relationship between server location and latency. These are not guaranteed figures — real values depend on the broker, the network route, and the time of day.

How to Test Latency (Ping / MT4 Connection)

Before deciding to move servers or troubleshoot, measure the real latency first. There are several easy ways to do this on both a PC and a VPS.

1. 1Check MT4/MT5 — the bottom-right corner of the program shows the connection status and the ms figure for the server you are logged in to; click it to see the ping details of each server
2. 2Use the ping command — open Command Prompt and type ping followed by the broker server's name/domain to see the round-trip value in ms (ask broker support for the server address)
3. 3Test repeatedly at different times — measure during both quiet market hours and news periods, because latency can differ a lot with network congestion
4. 4Compare before and after — measure from your home PC versus from the VPS to see how much moving to a VPS actually reduces latency

How to Genuinely Lower Latency (Practical Steps)

Once you know the real value, you can lower latency in several ways, starting with the factors that give the biggest impact: distance and server quality.

• Choose a server location near the broker's server — the most impactful factor; check which region the broker houses its servers in and match it
• Use a quality VPS instead of a home PC — a VPS in a data center has high-speed internet, a direct route, and is more stable than home or mobile connections
• Choose a provider with a stable, non-oversold network — ample resources and bandwidth keep latency consistent and free of spikes during peak times
• Use a wired (LAN) connection instead of Wi-Fi if you still run on your own machine — Wi-Fi adds delay and instability
• Reduce resource-heavy programs/indicators on the trading machine — a heavily loaded machine may process and send orders more slowly
• Keep your system and MT4/MT5 on stable versions — this reduces connection issues that make latency fluctuate