Libreprobe — Network truth beyond speed tests

Speed tests say you're fast.
Libreprobe shows why you're not.

Measures real application-layer performance — not synthetic speed test bursts.

👉 Try it instantly: https://libreprobe.pages.dev
(No signup, no tracking, runs in your browser)

Example output:

❌ Very high latency with instability
→ Interactive apps will struggle
→ Likely routing or congestion issue

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⚠️ Why speed tests lie

Speedtest result:
✔ 200 Mbps
✔ Low ping

Real experience:
✖ Lag spikes in games
✖ Call drops
✖ Buffering streams

→ The problem is instability, not speed.

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When to use

• Calls lag despite good speed results
• Gaming feels inconsistent or spiky
• Streaming buffers randomly
• Downloads stall or fluctuate
• Debugging network or application performance

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What Libreprobe exposes

Connection breakdown (Visibility)

IP, geolocation, ISP, ASN, TLS/HTTP versions, and edge PoP — from Cloudflare headers, no third-party APIs.

Sustained speed (Throughput)

Sustained download capacity via parallel streams. Reports median post-ramp speed, p95 peak, variance, ramp time, and transfer stats.

Latency & Jitter (Stability)

100 RTT probes at 100ms intervals. Measures median latency, jitter, p90 latency, and cold vs. warm handshake overhead. Live RTT and jitter charts with interpretation.

Classifies connection quality — not just reports numbers.

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Architecture

Based on fixed-interval RTT sampling and percentile analysis — not averages.

Browser → CF Edge Function → CF Edge Streams → Browser metrics pipeline

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Who this is for

If your internet "looks fast" but feels unreliable — this is for you.

• Developers debugging performance
• Network engineers investigating instability
• Advanced users diagnosing ISP behaviour

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Self-hosting

Requires:

• Cloudflare account
• Wrangler CLI
• One KV namespace binding

Quick deploy:

git clone https://github.com/grayguava/libreprobe.git
cd libreprobe

wrangler kv namespace create LIBREPROBE_THROUGHPUT_RL
# add binding to wrangler.toml

wrangler pages deploy .

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Screenshots

Libreprobe provides four diagnostic views:

Example output:

❌ Very high latency with instability
→ Interactive apps will struggle
→ Likely routing or congestion issue

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Methodology (short)

• Fixed-interval RTT avoids burst bias
• Multi-stream tests expose congestion collapse
• Percentile analysis beats averages

For full details, metric definitions, and caveats see:

docs/methodology/

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Versions

• Full : production UI identical to hosted version
• Skinless : logic-only bundle for embedding, testing, or custom frontends

Both bundles deploy the same way. See the deployment docs for details.

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Stack (full version)

Backend runs on Cloudflare Pages Functions (Worker runtime, V8 isolates). No servers or origin compute required.

• Connection data — Cloudflare request headers (CF-Ray, CF-IPCountry, etc.)
• Map — OpenStreetMap via CARTO, rendered with Leaflet
• Charts — Apache ECharts
• Frontend — Vanilla JS (ES modules), no framework, no build step

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Project structure

High-level layout:

libreprobe/
├── index.html                             # Home — visibility overview + map
├── info.html                              # Full connection info
├── throughput.html                        # Throughput test
├── stability.html                         # Stability test
├── screenshots/                           # README screenshots
│
├── assets/
│   ├── data/
│   │   └── cloudflare-edge-locations.json # IATA PoP → city + coordinates
│   │
│   ├── graphics/
│   │   ├── icon.svg
│   │   └── Logo.png
│   │
│   ├── js/
│   │   ├── apps/
│   │   │   ├── connectionInfoRenderer.js  # Renders connection data + Leaflet map
│   │   │   ├── getThroughput.js           # Throughput test UI and orchestration
│   │   │   └── getStability.js            # Stability test UI and orchestration
│   │   │
│   │   └── measurement/
│   │       ├── environment/
│   │       │   └── getConnectionInfo.js   # Fetches and parses edge headers
│   │       ├── rtt/
│   │       │   ├── handshake.js           # Cold and warm handshake measurement
│   │       │   ├── probe.js               # Single RTT probe
│   │       │   └── stability.js           # 100-probe RTT measurement loop
│   │       ├── shared/
│   │       │   ├── interpret.js           # Stability result interpretation
│   │       │   ├── interpretThroughput.js # Throughput result interpretation
│   │       │   └── sampler.js             # Shared sampling utilities
│   │       └── throughput/
│   │           └── measureDownlink.js     # Parallel stream download measurement
│   │
│   └── vendor/
│       ├── leaflet/                       # Leaflet.js + CSS
│       └── echarts/                       # ECharts (minified)
│
└── functions/
    └── api/
        ├── info/index.js                  # Connection info endpoint
        ├── ping/index.js                  # Latency probe endpoint
        └── stream/                        # Throughput stream endpoint
            ├── index.js
            ├── globals.js
            ├── shared.js
            └── [token].js

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Deployment

Libreprobe is a fully static site with Cloudflare Workers functions.
No frontend build step required.

The functions/api/ directory is deployed automatically by Cloudflare Pages as Workers.

For full deployment instructions and self-hosting notes see:

docs/deployment/

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Privacy

Libreprobe is stateless.

• No accounts
• No analytics
• No tracking
• No stored results
• No storage at edge
• No KV persistence except tokens

Connection metadata is processed in memory to generate responses and discarded immediately.

Full policy: https://libreprobe.pages.dev/privacy/

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Feedback

Open an issue if you tried Libreprobe and tell us:

• What confused you
• What broke
• What felt unclear
• Whether you used the hosted or self-hosted version

Be blunt. We want honest feedback.