Litmus

Precision Network Throughput Testing

Measure bandwidth, latency, jitter, packet loss, and data integrity between two machines. Available as a desktop app for Windows and a terminal application for Linux — self-contained, no runtime required.

What Litmus Measures

Every test produces a complete picture of network health with real-time metrics and professional-grade analysis.

Throughput

Average, minimum, and maximum bits per second across the test window.

Latency

Idle (pre-test baseline), loaded (during test), and post-test recovery measurements.

Jitter

RFC 3550 interarrival jitter calculation with per-sample timeline tracking.

Packet Loss

Per-packet sequence tracking with timestamped loss event detection.

Data Integrity

CRC32 verification — per-packet on UDP, stream-level on TCP.

Quality Score

Composite A through F letter grade derived from five weighted metrics.

Test Any Configuration

Mix and match protocols, directions, and stream counts to test exactly the scenario you need.

Protocol

  • TCP
  • UDP
  • Both (sequential)

Direction

  • Upload
  • Download
  • Bidirectional

Streams

  • 1–8 parallel connections
  • Per-stream tracking
  • Live aggregation

Certification Mode

One-click test suite that runs all six protocol/direction combinations in sequence, compiling results into a single certification PDF report with per-test grades and an overall pass/fail determination.

1.TCP Upload
2.TCP Download
3.TCP Bidirectional
4.UDP Upload
5.UDP Download
6.UDP Bidirectional

Network Quality Score

Every test receives a composite letter grade derived from five weighted metrics using a quadratic scoring curve.

Weighted Metrics

Bandwidth Stability35%

Threshold: min/max variance

Latency30%

Threshold: 100 ms

Jitter15%

Threshold: 10 ms

Packet Loss10%

Threshold: 1%

Data Integrity10%

Threshold: 0 corrupt packets

Grade Scale

A
Score: 90–100
B
Score: 75–89
C
Score: 60–74
D
Score: 40–59
F
Score: < 40

Scoring uses a quadratic curve — small deviations have minimal impact while values approaching the threshold drop the score sharply.

Professional Reports & Export

Automatic PDF report generation after every test. Eleven report designs, each available in light and dark mode.

Standard

Hero throughput banner with config/quality split layout

Executive Summary

Single-page brief with grade badge and sparkline

Comparison

Before/after with delta arrows and overlay chart

Gauge Dashboard

Semicircle gauges — one main, four mini

Technical

Dense three-column metric layout

SLA Compliance

Compliance percentage, headroom bars, pass/fail per metric

Landscape

A4 landscape with 35/65 sidebar layout

Certificate

Decorative wall certificate with shield badge

Timeline

Test lifecycle phases, warmup ramp, stability analysis

Score Card

Pentagon radar chart for five metrics

Diagnostic

Issue detection, severity badges, recommendations

JSON Export

Structured output with config, per-interval samples, and full result summary

CSV Export

One row per sample: timestamp, bitrate, direction, latency, jitter, and more

Advanced Controls

Fine-tune every aspect of your tests with professional-grade configuration options.

Bandwidth & Traffic

  • Bandwidth shaping (Kbit–Tbit)
  • DSCP/QoS marking (0–63)
  • Socket buffer size override
  • Warmup omit (0–60 seconds)

UDP Controls

  • Packet size (68–65,535 bytes)
  • Don't Fragment bit
  • Ramp-up pacing (0–2,000 ms)
  • Auto-detect ramp-up duration

Test Termination

  • Duration-based (seconds)
  • Byte count (K/M/G suffixes)
  • Packet count (UDP)
  • Interface binding

Data Patterns

  • Random (cryptographic)
  • Zeros / Ones / Alternating
  • Incrementing sequence
  • Microwave stress & custom byte

Charts & Visualization

  • Area, Line, Bar, Step, Gauge styles
  • 500 ms sample updates
  • Up to 4 simultaneous test runs
  • Auto-detect MTU (binary search)

Server & Network

  • Active connection monitoring
  • CPU usage with alert thresholds
  • Peer discovery & chat (LAN)
  • Server uptime & transfer statistics

Download Litmus

Self-contained executables — no runtime or dependencies required.

Windows

Windows 10/11 (64-bit)

Full-featured WPF desktop application with real-time charts, tabbed interface, and settings dialog.

Litmus.exe|191 MB

Linux

x86_64 binary

Terminal application with interactive TUI, headless mode, and JSON output for automation.

litmus-x64|100 MB

Quick Start

# Start a server

litmus -s

# 60-second TCP download test

litmus -c 192.168.1.100 -t 60

# 8 parallel UDP streams

litmus -c 10.0.0.5 --udp -P 8 -l 1500

# Full certification with report

litmus -c 10.0.0.5 --certify