Tailscale Performance Overhead Analysis

TL;DR
On 1 Gbps Ethernet: throughput overhead ~5.4% (941 → 890 Mbit/s). Added latency +0.259 ms (0.369 → 0.628 ms), a 70% relative rise but negligible absolute impact for most workloads.

Overview

Goal: quantify bandwidth and latency overhead when routing traffic through Tailscale versus a direct (unencrypted LAN) path.

Test Environment

Identical hardware / software on both endpoints:

OS: Debian GNU/Linux 13 (trixie) x86_64
Kernel: Linux 6.12.41+deb13-amd64
CPU: AMD Ryzen 5 3600 (12 threads) @ 4.21 GHz
Memory: 62.73 GiB
Link: 1 Gbps wired Ethernet
Test duration: 60 s (bandwidth), 15 probes (latency)

Methodology

Bandwidth

Tool: iperf3 (TCP, 1 MiB buffers, 60 s).
Command:

iperf3 -c [server_ip] -Z -4 -t 60 -l 1M

Latency

Tool: tcping (15 TCP connection RTT probes to an application port).
Command:

tcping -4 -c 15 [server_ip] 44430

Results

Bandwidth (Throughput)

Scenario	Throughput (Mbit/s)	Delta vs Direct	Overhead %
Direct	941	—	—
Tailscale	890	-51	-5.4%

Interpretation: Encryption / encapsulation plus userspace path introduce a modest ~5% reduction while still sustaining near line-rate for 1 Gbps.

Latency (Average RTT)

Scenario	Avg RTT (ms)	Delta (ms)	Relative Change
Direct	0.369	—	—
Tailscale	0.628	+0.259	+70.2%

Interpretation: Relative jump appears large due to very small baseline; sub-millisecond added latency remains insignificant for most interactive or bulk transfer use cases.

Analysis

Throughput impact aligns with expected crypto + encapsulation overhead on commodity CPU without offload.
Retransmissions higher over Tailscale session (436 vs 11) likely reflect altered packet pacing / window dynamics through the tunnel.
Latency addition (< 0.3 ms) is dominated by per-packet processing rather than path lengthening.

Conclusion

Tailscale introduces a small, measurable overhead: ~5% bandwidth reduction and +0.259 ms latency. For typical developer, self-hosting, or internal service scenarios this trade-off is favorable given simplified secure connectivity.

Raw Data

Full Logs (iperf3 & tcping)

Bandwidth Test (iperf3)

Via Tailscale

Connecting to host master, port 5201

[ 5] local [MASTER TAILSCALE IP] port 34212 connected to 100.64.0.9 port 5201
[ ID] Interval Transfer Bitrate Retr Cwnd
[ 5] 0.00-1.00 sec 107 MBytes 897 Mbits/sec 8 704 KBytes
[ 5] 1.00-2.00 sec 105 MBytes 880 Mbits/sec 4 584 KBytes
[ 5] 2.00-3.00 sec 104 MBytes 872 Mbits/sec 0 692 KBytes
[ 5] 3.00-4.00 sec 105 MBytes 882 Mbits/sec 312 559 KBytes
[ 5] 4.00-5.00 sec 107 MBytes 897 Mbits/sec 2 663 KBytes
[ 5] 5.00-6.00 sec 105 MBytes 881 Mbits/sec 5 558 KBytes
[ 5] 6.00-7.00 sec 107 MBytes 898 Mbits/sec 0 672 KBytes
[ 5] 7.00-8.00 sec 106 MBytes 888 Mbits/sec 1 764 KBytes
[ 5] 8.00-9.00 sec 106 MBytes 890 Mbits/sec 4 644 KBytes
[ 5] 9.00-10.00 sec 106 MBytes 889 Mbits/sec 4 519 KBytes
[ 5] 10.00-11.00 sec 107 MBytes 898 Mbits/sec 2 633 KBytes
[ 5] 11.00-12.00 sec 106 MBytes 890 Mbits/sec 0 734 KBytes
[ 5] 12.00-13.00 sec 106 MBytes 889 Mbits/sec 4 613 KBytes
[ 5] 13.00-14.00 sec 106 MBytes 889 Mbits/sec 0 717 KBytes
[ 5] 14.00-15.00 sec 107 MBytes 897 Mbits/sec 4 613 KBytes
[ 5] 15.00-16.00 sec 106 MBytes 888 Mbits/sec 0 717 KBytes
[ 5] 16.00-17.00 sec 107 MBytes 898 Mbits/sec 4 589 KBytes
[ 5] 17.00-18.00 sec 105 MBytes 882 Mbits/sec 0 696 KBytes
[ 5] 18.00-19.00 sec 106 MBytes 889 Mbits/sec 4 602 KBytes
[ 5] 19.00-20.00 sec 107 MBytes 897 Mbits/sec 0 709 KBytes
[ 5] 20.00-21.00 sec 105 MBytes 881 Mbits/sec 4 591 KBytes
[ 5] 21.00-22.00 sec 107 MBytes 897 Mbits/sec 0 698 KBytes
[ 5] 22.00-23.00 sec 106 MBytes 889 Mbits/sec 4 568 KBytes
[ 5] 23.00-24.00 sec 107 MBytes 897 Mbits/sec 0 681 KBytes
[ 5] 24.00-25.00 sec 106 MBytes 889 Mbits/sec 4 541 KBytes
[ 5] 25.00-26.00 sec 106 MBytes 889 Mbits/sec 0 657 KBytes
[ 5] 26.00-27.00 sec 107 MBytes 898 Mbits/sec 4 552 KBytes
[ 5] 27.00-28.00 sec 106 MBytes 889 Mbits/sec 0 667 KBytes
[ 5] 28.00-29.00 sec 106 MBytes 890 Mbits/sec 4 544 KBytes
[ 5] 29.00-30.00 sec 106 MBytes 889 Mbits/sec 0 662 KBytes
[ 5] 30.00-31.00 sec 107 MBytes 898 Mbits/sec 4 535 KBytes
[ 5] 31.00-32.00 sec 105 MBytes 881 Mbits/sec 0 654 KBytes
[ 5] 32.00-33.00 sec 107 MBytes 898 Mbits/sec 1 751 KBytes
[ 5] 33.00-34.00 sec 106 MBytes 889 Mbits/sec 4 636 KBytes
[ 5] 34.00-35.00 sec 106 MBytes 890 Mbits/sec 4 526 KBytes
[ 5] 35.00-36.00 sec 106 MBytes 889 Mbits/sec 0 648 KBytes
[ 5] 36.00-37.00 sec 107 MBytes 898 Mbits/sec 0 745 KBytes
[ 5] 37.00-38.00 sec 107 MBytes 897 Mbits/sec 4 626 KBytes
[ 5] 38.00-39.00 sec 105 MBytes 881 Mbits/sec 0 728 KBytes
[ 5] 39.00-40.00 sec 107 MBytes 898 Mbits/sec 4 601 KBytes
[ 5] 40.00-41.00 sec 106 MBytes 889 Mbits/sec 0 708 KBytes
[ 5] 41.00-42.00 sec 105 MBytes 882 Mbits/sec 5 612 KBytes
[ 5] 42.00-43.00 sec 107 MBytes 897 Mbits/sec 0 717 KBytes
[ 5] 43.00-44.00 sec 107 MBytes 898 Mbits/sec 4 588 KBytes
[ 5] 44.00-45.00 sec 106 MBytes 888 Mbits/sec 0 696 KBytes
[ 5] 45.00-46.00 sec 106 MBytes 890 Mbits/sec 4 564 KBytes
[ 5] 46.00-47.00 sec 106 MBytes 888 Mbits/sec 0 678 KBytes
[ 5] 47.00-48.00 sec 106 MBytes 889 Mbits/sec 4 562 KBytes
[ 5] 48.00-49.00 sec 106 MBytes 890 Mbits/sec 0 675 KBytes
[ 5] 49.00-50.00 sec 107 MBytes 897 Mbits/sec 4 548 KBytes
[ 5] 50.00-51.00 sec 105 MBytes 881 Mbits/sec 0 666 KBytes
[ 5] 51.00-52.00 sec 107 MBytes 897 Mbits/sec 0 763 KBytes
[ 5] 52.00-53.00 sec 106 MBytes 889 Mbits/sec 4 643 KBytes
[ 5] 53.00-54.00 sec 107 MBytes 898 Mbits/sec 0 744 KBytes
[ 5] 54.00-55.00 sec 107 MBytes 898 Mbits/sec 4 620 KBytes
[ 5] 55.00-56.00 sec 105 MBytes 881 Mbits/sec 0 722 KBytes
[ 5] 56.00-57.00 sec 106 MBytes 890 Mbits/sec 4 624 KBytes
[ 5] 57.00-58.00 sec 107 MBytes 897 Mbits/sec 0 728 KBytes
[ 5] 58.00-59.00 sec 106 MBytes 889 Mbits/sec 4 601 KBytes
[ 5] 59.00-60.00 sec 106 MBytes 889 Mbits/sec 0 706 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bitrate Retr

[ 5] 0.00-60.00 sec 6.22 GBytes 891 Mbits/sec 436 sender
[ 5] 0.00-60.01 sec 6.22 GBytes 890 Mbits/sec receiver

Direct Connection

Connecting to host [MASTER IP], port 5201

[ 5] local [SLAVE IP] port 36730 connected to [MASTER IP] port 5201
[ ID] Interval Transfer Bitrate Retr Cwnd
[ 5] 0.00-1.00 sec 113 MBytes 947 Mbits/sec 2 311 KBytes
[ 5] 1.00-2.00 sec 113 MBytes 948 Mbits/sec 3 311 KBytes
[ 5] 2.00-3.00 sec 112 MBytes 940 Mbits/sec 2 311 KBytes
[ 5] 3.00-4.00 sec 112 MBytes 940 Mbits/sec 2 311 KBytes
[ 5] 4.00-5.00 sec 112 MBytes 940 Mbits/sec 0 311 KBytes
[ 5] 5.00-6.00 sec 112 MBytes 940 Mbits/sec 0 311 KBytes
[ 5] 6.00-7.00 sec 113 MBytes 948 Mbits/sec 2 311 KBytes
[ 5] 7.00-8.00 sec 112 MBytes 940 Mbits/sec 0 311 KBytes
[ 5] 8.00-9.00 sec 112 MBytes 940 Mbits/sec 0 311 KBytes
[ 5] 9.00-10.00 sec 112 MBytes 940 Mbits/sec 0 311 KBytes
[ 5] 10.00-11.00 sec 112 MBytes 939 Mbits/sec 0 311 KBytes
[ 5] 11.00-12.00 sec 113 MBytes 948 Mbits/sec 0 311 KBytes
[ 5] 12.00-13.00 sec 112 MBytes 940 Mbits/sec 0 311 KBytes
[ 5] 13.00-14.00 sec 112 MBytes 940 Mbits/sec 0 311 KBytes
[ 5] 14.00-15.00 sec 112 MBytes 940 Mbits/sec 0 311 KBytes
[ 5] 15.00-16.00 sec 113 MBytes 948 Mbits/sec 0 311 KBytes
[ 5] 16.00-17.00 sec 112 MBytes 940 Mbits/sec 0 311 KBytes
[ 5] 17.00-18.00 sec 112 MBytes 940 Mbits/sec 0 311 KBytes
[ 5] 18.00-19.00 sec 113 MBytes 948 Mbits/sec 0 464 KBytes
[ 5] 19.00-20.00 sec 112 MBytes 940 Mbits/sec 0 464 KBytes
[ 5] 20.00-21.00 sec 112 MBytes 940 Mbits/sec 0 464 KBytes
[ 5] 21.00-22.00 sec 113 MBytes 948 Mbits/sec 0 464 KBytes
[ 5] 22.00-23.00 sec 112 MBytes 940 Mbits/sec 0 464 KBytes
[ 5] 23.00-24.00 sec 112 MBytes 940 Mbits/sec 0 464 KBytes
[ 5] 24.00-25.00 sec 113 MBytes 948 Mbits/sec 0 464 KBytes
[ 5] 25.00-26.00 sec 112 MBytes 940 Mbits/sec 0 464 KBytes
[ 5] 26.00-27.00 sec 112 MBytes 940 Mbits/sec 0 464 KBytes
[ 5] 27.00-28.00 sec 114 MBytes 956 Mbits/sec 0 677 KBytes
[ 5] 28.00-29.00 sec 111 MBytes 931 Mbits/sec 0 677 KBytes
[ 5] 29.00-30.00 sec 113 MBytes 948 Mbits/sec 0 677 KBytes
[ 5] 30.00-31.00 sec 111 MBytes 931 Mbits/sec 0 677 KBytes
[ 5] 31.00-32.00 sec 113 MBytes 948 Mbits/sec 0 677 KBytes
[ 5] 32.00-33.00 sec 112 MBytes 940 Mbits/sec 0 677 KBytes
[ 5] 33.00-34.00 sec 113 MBytes 948 Mbits/sec 0 677 KBytes
[ 5] 34.00-35.00 sec 112 MBytes 940 Mbits/sec 0 677 KBytes
[ 5] 35.00-36.00 sec 112 MBytes 940 Mbits/sec 0 677 KBytes
[ 5] 36.00-37.00 sec 112 MBytes 940 Mbits/sec 0 677 KBytes
[ 5] 37.00-38.00 sec 112 MBytes 940 Mbits/sec 0 677 KBytes
[ 5] 38.00-39.00 sec 113 MBytes 948 Mbits/sec 0 677 KBytes
[ 5] 39.00-40.00 sec 112 MBytes 940 Mbits/sec 0 677 KBytes
[ 5] 40.00-41.00 sec 113 MBytes 948 Mbits/sec 0 677 KBytes
[ 5] 41.00-42.00 sec 111 MBytes 931 Mbits/sec 0 677 KBytes
[ 5] 42.00-43.00 sec 112 MBytes 940 Mbits/sec 0 677 KBytes
[ 5] 43.00-44.00 sec 113 MBytes 948 Mbits/sec 0 677 KBytes
[ 5] 44.00-45.00 sec 112 MBytes 940 Mbits/sec 0 677 KBytes
[ 5] 45.00-46.00 sec 113 MBytes 948 Mbits/sec 0 677 KBytes
[ 5] 46.00-47.00 sec 111 MBytes 931 Mbits/sec 0 677 KBytes
[ 5] 47.00-48.00 sec 113 MBytes 948 Mbits/sec 0 677 KBytes
[ 5] 48.00-49.00 sec 112 MBytes 940 Mbits/sec 0 677 KBytes
[ 5] 49.00-50.00 sec 112 MBytes 940 Mbits/sec 0 677 KBytes
[ 5] 50.00-51.00 sec 113 MBytes 948 Mbits/sec 0 677 KBytes
[ 5] 51.00-52.00 sec 112 MBytes 940 Mbits/sec 0 677 KBytes
[ 5] 52.00-53.00 sec 111 MBytes 931 Mbits/sec 0 677 KBytes
[ 5] 53.00-54.00 sec 113 MBytes 948 Mbits/sec 0 677 KBytes
[ 5] 54.00-55.00 sec 113 MBytes 948 Mbits/sec 0 677 KBytes
[ 5] 55.00-56.00 sec 112 MBytes 940 Mbits/sec 0 677 KBytes
[ 5] 56.00-57.00 sec 111 MBytes 931 Mbits/sec 0 677 KBytes
[ 5] 57.00-58.00 sec 113 MBytes 948 Mbits/sec 0 677 KBytes
[ 5] 58.00-59.00 sec 112 MBytes 940 Mbits/sec 0 677 KBytes
[ 5] 59.00-60.00 sec 113 MBytes 948 Mbits/sec 0 677 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval Transfer Bitrate Retr

[ 5] 0.00-60.00 sec 6.58 GBytes 942 Mbits/sec 11 sender
[ 5] 0.00-60.00 sec 6.58 GBytes 941 Mbits/sec receiver

Latency Test (tcping)

Via Tailscale

TCPinging slave on port 44430

Reply from slave ([MASTER TAILSCALE IP]) on port 44430 TCP_conn=1 time=0.583 ms
Reply from slave ([MASTER TAILSCALE IP]) on port 44430 TCP_conn=2 time=0.649 ms
Reply from slave ([MASTER TAILSCALE IP]) on port 44430 TCP_conn=3 time=0.671 ms
Reply from slave ([MASTER TAILSCALE IP]) on port 44430 TCP_conn=4 time=0.511 ms
Reply from slave ([MASTER TAILSCALE IP]) on port 44430 TCP_conn=5 time=0.660 ms
Reply from slave ([MASTER TAILSCALE IP]) on port 44430 TCP_conn=6 time=0.626 ms
Reply from slave ([MASTER TAILSCALE IP]) on port 44430 TCP_conn=7 time=0.612 ms
Reply from slave ([MASTER TAILSCALE IP]) on port 44430 TCP_conn=8 time=0.536 ms
Reply from slave ([MASTER TAILSCALE IP]) on port 44430 TCP_conn=9 time=0.574 ms
Reply from slave ([MASTER TAILSCALE IP]) on port 44430 TCP_conn=10 time=0.917 ms
Reply from slave ([MASTER TAILSCALE IP]) on port 44430 TCP_conn=11 time=0.510 ms
Reply from slave ([MASTER TAILSCALE IP]) on port 44430 TCP_conn=12 time=0.712 ms
Reply from slave ([MASTER TAILSCALE IP]) on port 44430 TCP_conn=13 time=0.591 ms
Reply from slave ([MASTER TAILSCALE IP]) on port 44430 TCP_conn=14 time=0.649 ms
Reply from slave ([MASTER TAILSCALE IP]) on port 44430 TCP_conn=15 time=0.627 ms

--- slave ([MASTER TAILSCALE IP]) TCPing statistics ---
15 probes transmitted on port 44430 | 15 received, 0.00% packet loss
successful probes: 15
unsuccessful probes: 0
last successful probe: 2025-09-12 04:21:51
last unsuccessful probe: Never failed
total uptime: 15 seconds
total downtime: 0 second
longest consecutive uptime: 15 seconds from 2025-09-12 04:21:37 to 2025-09-12 04:21:52
retried to resolve hostname 0 times
rtt min/avg/max: 0.510/0.628/0.917 ms
--------------------------------------
TCPing started at: 2025-09-12 04:21:37
TCPing ended at: 2025-09-12 04:21:52
duration (HH:MM:SS): 00:00:15

Direct Connection

TCPinging [MASTER IP] on port 44430

Reply from [MASTER IP] ([MASTER IP]) on port 44430 TCP_conn=1 time=0.521 ms
Reply from [MASTER IP] ([MASTER IP]) on port 44430 TCP_conn=2 time=0.333 ms
Reply from [MASTER IP] ([MASTER IP]) on port 44430 TCP_conn=3 time=0.377 ms
Reply from [MASTER IP] ([MASTER IP]) on port 44430 TCP_conn=4 time=0.249 ms
Reply from [MASTER IP] ([MASTER IP]) on port 44430 TCP_conn=5 time=0.260 ms
Reply from [MASTER IP] ([MASTER IP]) on port 44430 TCP_conn=6 time=0.358 ms
Reply from [MASTER IP] ([MASTER IP]) on port 44430 TCP_conn=7 time=0.351 ms
Reply from [MASTER IP] ([MASTER IP]) on port 44430 TCP_conn=8 time=0.390 ms
Reply from [MASTER IP] ([MASTER IP]) on port 44430 TCP_conn=9 time=0.390 ms
Reply from [MASTER IP] ([MASTER IP]) on port 44430 TCP_conn=10 time=0.399 ms
Reply from [MASTER IP] ([MASTER IP]) on port 44430 TCP_conn=11 time=0.258 ms
Reply from [MASTER IP] ([MASTER IP]) on port 44430 TCP_conn=12 time=0.425 ms
Reply from [MASTER IP] ([MASTER IP]) on port 44430 TCP_conn=13 time=0.379 ms
Reply from [MASTER IP] ([MASTER IP]) on port 44430 TCP_conn=14 time=0.258 ms
Reply from [MASTER IP] ([MASTER IP]) on port 44430 TCP_conn=15 time=0.592 ms

--- [MASTER IP] TCPing statistics ---
15 probes transmitted on port 44430 | 15 received, 0.00% packet loss
successful probes: 15
unsuccessful probes: 0
last successful probe: 2025-09-12 04:22:24
last unsuccessful probe: Never failed
total uptime: 15 seconds
total downtime: 0 second
longest consecutive uptime: 15 seconds from 2025-09-12 04:22:10 to 2025-09-12 04:22:25
rtt min/avg/max: 0.249/0.369/0.592 ms
--------------------------------------
TCPing started at: 2025-09-12 04:22:10
TCPing ended at: 2025-09-12 04:22:25
duration (HH:MM:SS): 00:00:15

Overview#

Test Environment#

Methodology#

Bandwidth#

Latency#

Results#

Bandwidth (Throughput)#

Latency (Average RTT)#

Analysis#

Conclusion#

Raw Data#

Bandwidth Test (iperf3)#

Via Tailscale#

Direct Connection#

Latency Test (tcping)#

Via Tailscale#

Direct Connection#

Overview

Test Environment

Methodology

Bandwidth

Latency

Results

Bandwidth (Throughput)

Latency (Average RTT)

Analysis

Conclusion

Raw Data

Bandwidth Test (iperf3)

Via Tailscale

Direct Connection

Latency Test (tcping)

Via Tailscale

Direct Connection