Tej

Honest Internet Speed Test

tej (तेज़) — Hindi for "fast, swift"

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Why Tej?

Most speed test tools use compressible data that ISPs can optimize in transit, giving you inflated results. Tej uses incompressible random data to show your real internet speed.

Feature	Tej	Ookla	Fast.com
Incompressible data	Yes	No	No
Open source	Yes	No	No
Cross-platform (Desktop + Mobile)	Yes	Yes	Web only
Lightweight (<10MB binary)	Yes	No (~200MB)	N/A
No telemetry	Yes	No	No

Installation

Homebrew (macOS/Linux)

brew tap pm-bhatt/tej
brew install tej

or single line

brew install pm-bhatt/tej/tej

Cargo

cargo install tej-cli

Download Binary

Download pre-built binaries from Releases.

GUI App

Download from Releases for:

• macOS (Apple Silicon & Intel)
• Windows
• Linux (AppImage, deb)
• iOS (coming soon)
• Android (coming soon)

Web App (Browser)

Run directly in your browser - no installation needed:

Live URL: https://tej.pmbhatt.com/ (or deploy your own)

Features:

• Same honest measurements as CLI
• Runs entirely in browser (WASM)
• ~8KB total size
• No telemetry, no tracking

To run locally:

cd apps/tej-web
python3 -m http.server 8000
# Open http://localhost:8000

To build from source:

rustup target add wasm32-unknown-unknown
cargo install wasm-pack
./build-web.sh

Build from Source

git clone https://github.com/pm-bhatt/tej.git
cd tej

# CLI only
cargo build --release -p tej-cli

# GUI (requires Node.js)
cd apps/tej-gui
npm install
cargo tauri build

Usage

CLI

# Basic speed test
tej

# JSON output (for scripts)
tej --format json

# Customize connections
tej -c 8

# Skip upload test
tej --no-upload

# All options
tej --help

Example Output

Tej - Honest Speed Test
Testing with 6 parallel connections...

┌─────────────────┬────────────────┐
│ Metric          │ Value          │
├─────────────────┼────────────────┤
│ Server          │ SFO            │
│ Latency (avg)   │ 12.3 ms        │
│ Latency (min/max)│ 10.1 / 18.2 ms │
│ Jitter          │ 1.8 ms         │
│ Download        │ 245.67 Mbps    │
│ Upload          │ 98.34 Mbps     │
│ Packet Loss     │ 0.0%           │
└─────────────────┴────────────────┘

How It Works

1. Latency Measurement: 20 HTTP requests to Cloudflare's edge, discarding first 3 as warmup
2. Jitter Calculation: Mean absolute difference between consecutive samples (RFC 3550)
3. Download Test: 6 parallel HTTP GET streams with incompressible random data
4. Upload Test: 6 parallel HTTP POST with locally-generated random bytes
5. Packet Loss: HTTP timeout-based approximation over 20 requests

Why Cloudflare?

• 300+ edge locations worldwide
• Consistent, reliable infrastructure
• Representative of real-world CDN performance
• cf-ray header tells you exactly which datacenter served you

Architecture

tej/
├── crates/
│   ├── tej-core/     # Core measurement library
│   └── tej-cli/      # Terminal CLI
└── apps/
    └── tej-gui/      # Tauri 2.0 desktop/mobile app
        ├── src-tauri/    # Rust backend
        └── src/          # Svelte frontend

Metrics Explained

Metric	What It Measures
Download	Throughput receiving data (Mbps)
Upload	Throughput sending data (Mbps)
Latency	Round-trip time to server (ms)
Jitter	Variation in latency (ms) - lower is better
Packet Loss	Percentage of failed requests

Contributing

We welcome contributions! Please see CONTRIBUTING.md for guidelines.

# Run tests
cargo test --workspace

# Run clippy
cargo clippy --workspace -- -D warnings

# Format code
cargo fmt --all

License

MIT License - see LICENSE for details.

Acknowledgments

• Cloudflare for providing the speed test infrastructure
• Built with Rust, Tauri, and Svelte