Most browser tools send your data to a server. These don't.
Browser-based utility tools for developers, hardware diagnostics, and security work.
Everything runs client-side. No uploads, no accounts.
Official Website · Blog · Changelog
| Tool | Description | Release date |
|---|---|---|
| Monitor & Display Test Suite | Dead pixel patterns, backlight bleed, motion ghosting, fullscreen test modes | 2026-04-15 |
| Input Lag & Mouse Polling Rate Tester | Browser input latency and mouse polling rate via PointerEvent API | 2026-04-24 |
| Webcam A/V Sync & Latency Meter | Millisecond offset between webcam and microphone, OBS-ready output | 2026-05-20 |
| Webcam Lighting & Framing Analyzer | Lighting balance, face framing, and resolution diagnostics | 2026-04-22 |
| Web MIDI Keyboard & Latency Tester | Dead keys, ghost notes, and USB-to-browser MIDI input latency | 2026-04-24 |
| Gamepad & Joystick Drift Tester | Analog stick drift, dead zone visualization, button diagnostics | 2026-04-30 |
| Live Signal Debugger (coming) | Real-time USB/Serial/Bluetooth signals from Arduino, sensors, MIDI controllers | 2026-08* |
| WebUSB Hardware Flasher (coming) | Flash firmware to ESP32, Arduino, and Raspberry Pi Pico in-browser | 2026-08* |
| Tool | Description | Release date |
|---|---|---|
| JWT Decoder | Inspect header, payload, and expiry of any JWT token | 2026-04-24 |
| Cron Expression Parser | Translate cron syntax to plain English with next-run preview | 2026-04-25 |
| Base64 Encoder / Decoder | Encode and decode text or files to Base64 | 2026-05-06 |
| SQL Data Workbench | Query local files with SQL: Parquet, Arrow, Feather, Avro, DBF, Excel, CSV, JSON | 2026-05-16 |
| Big Log Explorer | Filter, search, and graph 500 MB+ log and JSONL files via Web Workers and IndexedDB | 2026-05-19 |
| Prompt Token Counter | Token count and context window usage for GPT-4o, Claude, and Gemini models | 2026-05-19 |
| Hash Generator | MD5, SHA-1, SHA-256, SHA-512, and HMAC computation | 2026-05-20 |
| UUID Generator | UUID v1, v4, and v7 in five display formats, cryptographically random | 2026-06-28 |
| JSON Formatter & Validator | Pretty-print, minify, and validate JSON with syntax highlighting | 2026-07-08 |
| Regex Tester | Live match highlighting and group capture view | 2026-07-07 |
| Text / Code Diff Viewer (coming) | Side-by-side and unified diff with line-level highlighting | 2026-07* |
| Binary Package Differ (coming) | Diff two ZIP archives or build artifacts: file tree, size delta, byte-level changes | 2026-07* |
| WASM Binary Inspector (coming) | Decompile WebAssembly to WAT, memory map, exports and imports | 2026-07* |
| Tool | Description | Release date |
|---|---|---|
| File Hash Verifier | SHA-256, SHA-512, SHA-1, and MD5 checksums compared against a published hash | 2026-04-23 |
| EXIF & Image Metadata Scrubber | Strip GPS coordinates, timestamps, and device data from images | 2026-04-23 |
| Browser Fingerprint Inspector | Canvas hash, WebGL renderer, audio fingerprint, fonts, and 30+ leak signals | 2026-05-04 |
| PII Scrubber | Detect and tokenize PII, secrets, and internal data before sending to AI | 2026-05-08 |
| Offline OCR & Document Redactor | Extract text and redact sensitive regions via Tesseract WASM | 2026-05-13 |
| X.509 Certificate Inspector | Validity, SANs, key algorithm, chain depth, and expiry from PEM or DER input | 2026-05-19 |
| Cloud Config Sanitizer | Validate Kubernetes, Terraform, and YAML manifests, detect secrets and security smells | 2026-05-19 |
| URL Encoder / Decoder | Percent-encode and decode URLs and query strings with component parsing | 2026-06-06 |
| Password Entropy Analyser | Shannon entropy, zxcvbn pattern analysis, and GPU crack-time estimates | 2026-06-09 |
| Quantum-Safe Encryptor (coming) | Post-quantum encryption and decryption via Kyber/Dilithium WASM | 2026-07* |
| Build Integrity Verifier (coming) | SHA-256 and BLAKE3 artifact comparison with functional content diff | 2026-07* |
| Local Secret Scanner (coming) | Scan code, configs, and ZIP archives for API keys, tokens, and credentials | 2026-07* |
| Tool | Description | Release date |
|---|---|---|
| Microphone Quality, Noise & Latency Tester | Noise floor, clipping, frequency response, echo loopback, and round-trip latency | 2026-04-22 |
| Speaker Frequency Sweep & Resonance Tester | 20 Hz to 20 kHz sweep to find resonances, rattle points, and drop-off frequencies | 2026-04-24 |
| Decibel Calculator | Convert between dB, watts, volts, and SPL with formula reference | 2026-05-08 |
| Tool | Description | Release date |
|---|---|---|
| Resistor Colour Code Calculator | 4-band, 5-band, and 6-band decoding with tolerance, temperature coefficient, E-series | 2026-04-24 |
| Engineering Unit Converter | SI and imperial units across 17 physical dimensions | 2026-05-02 |
| Electricity Unit Converter | Charge, current, voltage, resistance, capacitance, inductance across 15 dimensions | 2026-05-02 |
| Ohm's Law Calculator | Solve for voltage, current, resistance, or power from any two values | 2026-05-07 |
| Aspect Ratio Calculator | Display resolutions, scaling, and letterbox bars for any ratio | 2026-05-07 |
| Tool | Description | Release date |
|---|---|---|
| Readability Analyser | Flesch-Kincaid Grade, Flesch Reading Ease, and SMOG with sentence-level highlights | 2026-04-27 |
| Case Converter | camelCase, snake_case, SCREAMING_SNAKE, kebab-case, Title Case, PascalCase | 2026-05-07 |
| Reading Time Calculator (coming) | Reading time estimate at adjustable WPM targets | 2026-07* |
| Markdown Preview (coming) | Live-render Markdown with clean typeset output and copy-as-HTML export | 2026-07* |
| Tool | Description | Release date |
|---|---|---|
| Color Format Converter | Convert between HEX, RGB, HSL, HSV, OKLCH, and CSS named colours | 2026-05-02 |
| CSS Gradient Builder | Visual linear, radial, and conic gradient editor with live CSS output | 2026-06-07 |
| WCAG Contrast Checker | AA and AAA contrast ratio testing with hex, RGB, and HSL input | 2026-07-09 |
| Tool | Description | Release date |
|---|---|---|
| IPv4 / IPv6 Subnet & CIDR Calculator | Network ranges, broadcast addresses, and host counts for IPv4 and IPv6 | 2026-05-06 |
| URL Parser & Inspector | Decompose any URL into protocol, host, path, query params, and fragment | 2026-05-03 |
| P2P Network Tester | WebRTC peer-to-peer latency, jitter, and packet loss between two browsers | 2026-05-13 |
| IndexNow URL Submitter | Submit URLs to Bing, Yandex, Naver, and more via IndexNow | 2026-05-23 |
| MIME Type Reference | Searchable MIME database with extension mapping and RFC sources | 2026-05-31 |
| HTTP Status Code Reference | Searchable reference for all HTTP 1xx to 5xx codes with usage notes | 2026-05-20 |
* Planned release
- Local-First Data Analysis in the Browser: SQL Workbench and Big Log Explorer for Zero-Upload Analytics - Run SQL on Parquet, CSV, and JSON in your browser, then combine it with Big Log Explorer for a zero-upload analytics stack that keeps your data local.
- Finding the Correct MIME Type for Any File Before You Serve or Upload It - Look up the exact MIME type for any file, extension, or keyword, then copy a correct server directive, with no upload and no server round-trip.
- Polling Rate Reality Check: How to Measure Your Mouse Hz Locally Before You Trust That 8000Hz Claim - Measure your mouse's actual polling rate locally in the browser before you buy based on an 8000Hz marketing claim.
- Reading HTTP Status Codes Like a Backend Engineer: A Local Reference Guide You Can Use Without a Network - Learn to read HTTP status codes by class, distinguish confusing code pairs, and apply the right codes in API design and six popular frameworks.
- Letterboxing and Aspect Ratio Math for Video and Photo Crops - Predict letterbox and pillarbox bar sizes before export, choose the right delivery ratio per platform, and verify dimensions with a client-side calculator.
- Building Accessible, Contrast-Safe Color Systems in CSS Using OKLCH and WCAG - Learn to build a complete, contrast-safe color system in the browser with OKLCH and WCAG 2.1, from base color to CSS and Tailwind v4 tokens.
Built with Astro and TypeScript. Installable as a PWA.