Tester Tools

Test inputs and endpoints with handy utilities: regex testers, HTTP/API checks and more—right in the browser for efficient development and debugging workflows.

45 tools available

Audio Tools 1

Audio Compare

Compare two audio files with AB testing: integrated LUFS, true peak dBTP, loudness match and spectral analysis. MP3 vs FLAC, bitrate and master QC.

Calculators 5

Health & Fitness 5

Breathing exercise

Guided breathing timer with box breathing (4-4-4-4), 4-7-8 relaxing, energizing 4-2-4 and calming 4-4-6 patterns. Reduces stress, helps sleep — runs in your browser.

Eye exercise

Free 20-20-20 rule timer for digital eye strain relief. Every 20 minutes, look 20 feet away for 20 seconds. Reduces dry eyes, headaches and Computer Vision Syndrome.

Kegel exercise timer

Free Kegel exercise timer for men and women. Strengthen pelvic floor muscles with guided squeeze and release cycles, adjustable hold times, reps and sets.

Plank Challenge

Free plank challenge timer with customizable hold and rest periods, set tracking, and guided beginner/intermediate/advanced presets. Build core strength in your browser.

Tabata HIIT timer

Free Tabata and HIIT interval timer. Classic 20/10 × 8, 30/30, 45/15 presets or custom work/rest, with audio cues and round tracking. Runs in your browser.

Color Tools 2

Color Blindness Simulator

Simulate 9 types of color vision deficiency on images or palettes. Test protanopia, deuteranopia, tritanopia, achromatopsia. Side-by-side compare, download.

Color Contrast Checker

Free WCAG 2.1 & APCA color contrast checker. Test text and background for AA/AAA accessibility, with a size-driven verdict for ADA & Section 508 compliance.

Developer Tools 6

Testing & Debugging 4

XPath & CSS Selector Tester

Online XPath evaluator and querySelectorAll tester for HTML/XML — instant match count, real highlighting, and copy-as-code for Scrapy, Selenium and Playwright.

WebSocket Tester

Connect to any ws:// or wss:// endpoint, send/receive messages live, see full history with timestamps. For debugging chat, GraphQL subs, MQTT-over-WS.

API Request Tester

Browser REST client: GET/POST/PUT/PATCH/DELETE, custom headers, JSON body, response timing, and one-click Copy as cURL. Free Postman-lite tester.

Regex Tester

Free online regex tester with live matching, named capture groups, lookahead/lookbehind, and a replace/substitution mode using $1 and $<name> tokens.

Utilities 2

Robots.txt Tester

Test robots.txt rules with RFC 9309 group selection and Allow/Disallow precedence. Bulk-check URLs per bot, export CSV. Blocking is not deindexing.

Password Strength Tester

Check password strength with real-time entropy and brute-force crack-time analysis. Pick a GPU attacker model, test NIST 800-63B, generate secure passwords.

File Tools 1

File Compare

Compare two text, code, JSON or CSV files line by line with syntax highlighting. Ignore whitespace, case or CRLF/LF. 100% in-browser, no upload.

Hardware Tools 28

Connectivity 4

Network Quality

Test live WiFi and network quality: connection type, effective speed, downlink, round-trip time and jitter via the Network Information API, with CSV export.

Bluetooth Signal Tester

Scan and connect to nearby BLE devices in your browser via Web Bluetooth. Read GATT services and characteristics, monitor RSSI signal strength.

NFC Tester

Web NFC diagnostic tool: read NDEF records and tag serial/UID, write text/URI, lock tags, export CSV/JSON QA reports. NTAG215 & MIFARE on Chrome Android.

Speed Test

Free browser-based internet speed test, no app needed. Measure download & upload Mbps, ping, jitter & packet loss, plus your IP and ISP, in real time.

Diagnostics 6

Battery Tester

Free browser battery tester: read live charge level and charging status (Chrome/Edge/Opera only). The browser cannot read cycle count or wear — use the built-in SoH estimator.

Refresh Rate

Test your screen refresh rate online: measure 60, 120, 144, 165, 240, 360 Hz with frame-time chart, jitter stats and CSV/JSON export. Is my monitor 144hz? Free.

Screen Tester

Free monitor & phone screen test for dead pixels, stuck pixels, backlight bleed and OLED burn-in. Fullscreen RGB patterns, no install, 100% private.

Webcam Tester

Free webcam tester with a 10s FPS stability test and PASS/FAIL verdict. Measure real FPS, dropped frames and resolution, then export a CSV/JSON QA report.

Audio Latency Tester

Free browser audio latency tester. Reports Web Audio base + output latency in ms, sample rate and buffer size, with CSV/JSON export and pass/fail check.

Gamepad Tester

Test PS4, PS5, Xbox & Switch controllers for stuck buttons, analog stick drift, and trigger response. Record a pass/fail diagnostic and export CSV/JSON.

Input Devices 5

Mouse Tester

Free mouse tester: button, scroll-wheel and double-click chatter test with pass/fail verdict, CSV/JSON export, plus refresh-limited movement sampling.

CPS Test

Free CPS test measuring clicks per second for gaming and hardware QA: check mouse click speed, diagnose double-click chatter, jitter, switch wear and latency.

Keyboard Tester

Type to see every key light up on a visual layout (QWERTY/AZERTY, Windows/Mac). Detect stuck keys, ghosting, plus an NKRO / key rollover test. Free.

Reaction Time Test

Free online reaction time test. No install, works on phone & desktop, 100% private. Visual & audio modes with median, SD and CSV/JSON export.

Typing Speed Test

Free typing speed test: live WPM, net WPM, CPM and real accuracy. Words, sentences, quotes and code modes, 30-300s runs, private offline, CSV/JSON export.

Performance 4

Storage Test

Free browser storage benchmark using IndexedDB and localStorage. Measure read/write MB/s, per-op latency and run multiple passes to see variance.

Memory Speed Test

Private in-browser JavaScript/V8 memory benchmark. Multi-run sampling with median, stddev and a geometric-mean index. Read ops/sec, not native RAM bandwidth.

GPU Benchmark

Test graphics card performance with WebGL2 rendering, shader computations, particle simulations and 3D graphics. Measure GPU speed, FPS and export results.

CPU Benchmark

Free in-browser single-thread CPU benchmark. Six JavaScript workloads (primes, sort, matrix, hash, FP) score your processor, exportable to CSV/JSON. No install.

Sensors 9

Shake Detector

Test your phone's accelerometer and diagnose shake faults after drops or water damage. Read live g-force and m/s², adjust sensitivity, and export a CSV report.

Compass Calibration

Calibrate phone compass: compare magnetometer with sensor-fusion heading, capture true north reference, measure deviation after figure-8 motion.

Sound Level Meter

Free online sound level meter: measure relative dB with your mic, log min/max/average, calibrate against a reference, and export a timestamped CSV.

Orientation Tester

Test device orientation, gyroscope and compass with live 3D visualization. Monitor alpha/beta/gamma tilt, check sensor calibration, and export a QA session log.

Ambient Light Tester

Test your device ambient light sensor: live lux reading, analog meter, min/max/avg stats and CSV/JSON export. Chrome/Android only — not iOS or Firefox.

Proximity Sensor Tester

Test a proximity sensor in your browser over HTTPS, log near/far transitions and distance, and export CSV/JSON. Note: most browsers and iOS lack a web proximity API.

Gyroscope Tester

Read live DeviceOrientation alpha/beta/gamma angles in degrees on phones and tablets, with a 3D cube, compass heading and CSV/JSON data export.

Magnetometer Tester

Test your phone magnetometer sensor: live microtesla X/Y/Z readings, check against Earth's 25-65 µT field, spot hard-iron interference, plus CSV/JSON export.

Accelerometer Tester

Test your phone or laptop accelerometer in real time: live X, Y, Z acceleration in m/s², 3D vector, gravity & motion magnitude, peak tracking, CSV export.

PDF Tools 1

PDF Compare

Compare two PDF files online with page-by-page text diff. Spot changed words, clauses and metadata between PDF revisions, free and in your browser.

Text Tools 1

Text Difference

Free online diff tool to compare two texts side by side. See additions, deletions, and a similarity match percentage by line, word, or character.