London to Paris Latency, Ping & RTT | AS203314
London to Paris ping and RTT: 6.3 ms, 0.12 ms jitter, 3.37 ms fiber floor, and 53.5% efficiency across AS203314. Updated 2026-07-19.
🇬🇧 This page compares the published ping and round-trip time (RTT) from London (LON) to 🇫🇷 Paris (PAR) with vacuum and optical-fiber physical limits.
Latency Summary
| Metric | Value |
|---|---|
| RTT | 6.3 ms |
| Jitter | 0.12 ms |
| Packet Loss | 0.12% |
| Standard Fiber Floor | 3.37 ms |
| Fiber Efficiency | 53.5% |
| Latency Tier | Ultra-Low |
| Source Region | Europe |
| Destination Region | Europe |
Theoretical Fiber Latency
The public physical reference uses the GeoNames city centres for London (51.50853, -0.12574) and Paris (48.85341, 2.34880). It does not disclose either facility address.
| Physical Reference | Value |
|---|---|
| WGS-84 geodesic distance | 344.1 km |
| Vacuum RTT floor | 2.3 ms |
| Standard fiber RTT floor () | 3.37 ms |
| Low-latency fiber material floor | 3.36 ms |
| Engineering floor (5% path allowance) | 3.54 ms |
| Research 1.33× mapped-fiber reference | 4.48 ms |
| Estimated unamplified path loss | 72.3 dB |
| Transparent optical spans / inline amplifiers | 5 / 4 |
| Published RTT inflation over fiber floor | 1.87× |
Attenuation is used to estimate the number of 80 km optical spans; it does not directly slow light. See the full theoretical fiber latency, GeoNames, attenuation, and amplifier methodology.
Stability & Trend
The following estimated indicators summarize route stability for the current publication period and are intended for comparative planning rather than SLA evaluation.
| Stability Indicator | Value |
|---|---|
| Minimum RTT | 6.2 ms |
| Median RTT (p50) | 6.3 ms |
| 95th percentile RTT (p95) | 6.5 ms |
| Maximum RTT | 6.6 ms |
| Jitter | 0.12 ms |
| Packet loss | 0.12% |
RTT trend
Estimated route stability across the selected time window.
- Average
- 6.3 ms
- Minimum
- 6.2 ms
- Maximum
- 6.3 ms
- Average loss
- 0.03%
Route Context
- Departure PoP: London (LON)
- Destination PoP: Paris (PAR)
- Region overview: Europe → Europe
- Full global matrix: Backbone Latency Matrix
- Physical methodology: Theoretical Fiber Latency
Related City-Pair Routes
- Reverse direction: Paris to London latency and RTT — 6.3 ms
- London to Amsterdam latency and RTT — 5.1 ms
- London to Frankfurt latency and RTT — 12.4 ms
- London to Berlin latency and RTT — 16 ms
- London to Marseille latency and RTT — 17.3 ms
- London to Moscow latency and RTT — 42.7 ms
About This Measurement
Published RTT reflects best-case backbone path behavior. End-user latency also depends on local access networks, congestion, routing policy, and traffic engineering. Stability indicators are comparative estimates, and none of these values is an SLA.
Data auto-generated on July 19, 2026. Explore the full interactive latency matrix or browse more city-pair routes.