ByteScope
Free online developer tools — no install, no signup. Everything runs in your browser, so your files never leave your device.
Your files never leave your browser.
TYPE QUEST — playable demo
Type the code. Watch it come alive.
A typing game where every keystroke builds a real, runnable mini project — while it clocks your typing speed. The faster you type, the faster you write code. Try this one right here.
every character you type builds this pane — the finished code runs right here
Tools
Image tools
Image ↔ Base64 Converter
Batch convert images to Base64 data URIs — and decode Base64 back to images.
● live · /image-base64
Compress Image
Type the size you need — 200 KB, 1 MB, 5 MB — and the quality is searched until the file fits.
● live · /image-compress
Image Format Converter
Batch convert between PNG, JPEG, WebP, AVIF and GIF — with live size feedback.
● live · /image-convert
Image Pixel Diff
Compare two images pixel by pixel — diff, blend, swipe, onion skin and blink.
● live · /image-diff
Image Inspector
Magnify, pick pixel colors, and record sample points — HEX, RGB, HSL and OKLCH.
● live · /image-inspector
EXIF Viewer
Read every EXIF tag in a photo — body, lens, exposure, the software field and GPS coordinates — without the file leaving your browser.
● live · /exif-viewer
Remove EXIF
Strip EXIF, GPS and IPTC data at the byte level — the pixels come out bit-identical, because nothing is ever re-encoded.
● live · /remove-exif
Redact Screenshot
Paste a screenshot, cover the private parts, copy it straight back — with no blur on offer, because blurred text can be reconstructed.
● live · /redact-screenshot
ID Photo Maker
Six verified sizes, guides you line yourself up with, and a 4×6 sheet to print.
● live · /id-photo
Batch Image Converter
Batch convert entire folders of images between formats — locally, with zero uploads.
● live · /batch-image-convert
Photo Organizer
Sort photos by EXIF capture date into organized folders and separate screenshots.
● live · /photo-organizer
Remove Background
Cut a subject out locally. No account, no upload, a transparent PNG when you are done.
● live · /remove-background
Restore Old Photos
Sharpen a faded print and, if you want, give it colour — without handing it to a stranger's site.
● live · /photo-restore
Image to Text
Chinese OCR that stays on this device — receipts, phone photos, no account.
● live · /image-to-text
Eyedropper
Pick any color from your screen into hex, rgb, hsl, and oklch with WCAG contrast and palette export.
● live · /eyedropper
Video tools
Subtitle Converter
Convert, retime and repair subtitle files — SRT ↔ VTT ↔ ASS ↔ SBV, locally.
● live · /subtitle-converter
Video Info Inspector
Drop a video, get the full spec sheet — and the reason it won't play somewhere.
● live · /video-info
Screen Recorder
Record your screen — free, no watermark, no install, nothing uploaded.
● live · /screen-recorder
Subtitle Sync
Late subtitles get a shift, drifting subtitles get a two-point stretch — fixed locally, nothing uploaded.
● live · /subtitle-sync
Batch Video Converter
Batch convert GIF animations and MP4 videos across entire folders — locally.
● live · /batch-video-convert
Video Subtitles
Local Gemini Nano turns a recording into SRT or VTT — the file never leaves this tab.
● live · /video-subtitles
Live Subtitles
Share the tab, tick Share tab audio, and read the stream in your language — all on this machine.
● live · /live-subtitles
Subtitle Translate
Translate a YouTube transcript or an SRT/VTT file in this tab — bilingual output, nothing uploaded.
● live · /subtitle-translate
Codec Check
HEVC browser support test and AV1 codec check — hardware vs software decode, in this tab.
● live · /codec-check
DRM Check
Widevine test and DRM check — L1, L2 or L3, HDCP 2.2, and the Netflix 480p problem, in this tab.
● live · /drm-check
Device & connection diagnostics
Display & Monitor Test
Check your screen for defects and read out what your display really supports.
● live · /screen-test
Webcam Test
See your camera working — and what resolution and frame rate it really delivers.
● live · /webcam-test
Video Call Check
Three steps, one verdict: you're ready for the meeting — or here's exactly what to fix.
● live · /call-ready
Keyboard Tester
Press every key, watch it light up — and catch rollover limits and chattering switches.
● live · /keyboard-test
Gamepad Tester
Plug in a controller, press a button — then measure what your sticks are really doing.
● live · /gamepad-test
WebRTC Connection Tester
Not just "does WebRTC work" — see why it doesn't, and what to do about it.
● live · /webrtc-test
Printer Test Page
One sheet that shows what your printer is doing wrong — color, black ink, alignment and hairlines, printed straight from the browser's own dialog.
● live · /print-test-page
Mouse Test
Five buttons, a chatter histogram, a notch-exact wheel counter and an honest polling-rate estimate — one bench for the mouse you're about to blame.
● live · /mouse-test
Speaker Test
Left, right, sweep, pan and bass — a bench of test tones for the speakers you just wired up, generated live in the browser with nothing to download.
● live · /speaker-test
Headphone Test
Swapped sides, a quieter ear, bass that never shows up — check a new pair of headphones before the return window closes, straight from the browser.
● live · /headphone-test
Live Captions
Captions for what you say — or for what your computer is playing: subtitle your own talk as you speak, or float live captions and a translation over a stream in a language you don't speak.
● live · /live-captions
Keep Screen Awake
Keep the screen on in this tab — prevent the screen from sleeping with a screen wake lock. No sleep online; coverage shown when the tab is backgrounded.
● live · /keep-screen-awake
Touch Test
Touch screen test in this tab: multi-touch trails, a dead-spot grid, and browser event sample rate. Test touch screen response with a finger or a mouse.
● live · /touch-test
Pen Pressure Test
Test drawing tablet and stylus pen pressure online: live pressure curve, tilt angles, twist, and estimated hardware pressure levels.
● live · /pen-pressure-test
Built-in AI Test
Probe Translator, Summarizer, Language Detector and Prompt API in this tab — nothing uploaded.
● live · /built-in-ai-test
HDR Test
HDR test online — is this screen really HDR? The numbers follow the window onto another display.
● live · /hdr-test
Hardware bench
Serial Monitor & Plotter
Talk to a dev board over USB serial — terminal, HEX dump and live plots, right in the browser.
● live · /serial-monitor
ESP Firmware Flasher
Flash ESP32 / ESP8266 firmware straight from your browser — detect the chip, write .bin files, back up flash. No IDE, no esptool install.
● live · /esp-flasher
Firmware Installer
Install popular open-source firmware on an ESP board in one click — connect over USB, pick a version, done.
● live · /install
MicroPython Web IDE
Program MicroPython and CircuitPython boards from the browser — REPL, code editor and file manager, nothing to install.
● live · /micropython
MIDI Tester & Monitor
Plug in a MIDI keyboard or controller and see every note, knob and pedal in real time.
● live · /midi-test
Web ADB Toolkit
Talk ADB to your Android over USB from the browser — device info, files, APK sideload, live logcat and a shell.
● live · /web-adb
AVR / Arduino Uploader
Flash a compiled .hex to an Arduino Uno, Nano or Mega straight from the browser — STK500 over Web Serial, with read-back verify.
● live · /avr-uploader
Serial Protocol Playground
Send arbitrary bytes over serial, capture the reply, and reverse-engineer the protocol — right in the browser.
● live · /serial-playground
HID Report Descriptor Inspector
Plug in a HID device and read exactly what it tells the host — the decoded descriptor, a bit-level field map and live input reports.
● live · /hid-inspector
BLE GATT Explorer
Connect to any BLE device and walk its GATT tree — read, decode, write and subscribe, right in the browser.
● live · /ble-explorer
USB Device Identifier
Type a VID/PID and get the names behind it, or plug a device in and read every descriptor the browser will show you.
● live · /usb-device-info
NFC Reader
NFC tag reader online — write an NFC tag without an app, in Android Chrome. Local only.
● live · /nfc-reader
Web ADB workstation
● live · /web-adb/*
One USB cable, thirteen pages: everything below talks ADB straight from the browser, with nothing installed on the phone.
Other tools
APK Analyzer
Inspect an Android APK's manifest, permissions, signature, symbols and code — locally.
● live · /apk-analyzer
Hex Viewer / Editor
View and edit binary files in your browser — hex, decimal or binary, vim-style.
● live · /hex-editor
Password Generator
Strong random passwords, passphrases and PINs — generated locally, never transmitted.
● live · /password-generator
File Hash Calculator
Hash files with every common algorithm at once and verify checksums — locally.
● live · /file-hash
File Type Identifier
Find out what a file really is — magic-number detection, locally.
● live · /file-type
Timestamp Converter
Unix time ↔ human time, with the timezones you care about side by side.
● live · /timestamp
Archive Inspector
See exactly what's inside an archive — without extracting it or uploading it.
● live · /archive-inspector
Extract Archive
Unpack zip, rar, 7z and tar.gz right in the browser — passwords stay local, and dangerous paths are stopped at the door.
● live · /extract-archive
SQLite Viewer
Browse tables, run queries, build them visually — your database stays on your machine.
● live · /sqlite-viewer
Certificate Decoder
Paste a certificate, read everything in it — and find out why the chain is broken.
● live · /certificate-decoder
Certificate Generator
Self-signed certs, CSRs and a browser-based local CA — private keys never leave your machine.
● live · /certificate-generator
Type Quest
Type real code, watch it come alive next to you — and find out how fast you really type.
● live · /type-quest
QR File Transfer
Beam a file from one screen to another camera — no network, no cable, no pairing, no account. Just light.
● live · /qr-file-transfer
Subnet Calculator
Paste a CIDR, a bare address, or an address and a netmask — IPv4 and full IPv6, all in your browser.
● live · /subnet-calculator
Bitwise Calculator
AND, OR, XOR, shifts and a clickable bit grid — plus a bitfield decoder for the register in front of you.
● live · /bitwise-calculator
Binary Diff
Drop in two firmware builds, two disk images or two config dumps — byte-level comparison, entirely in your browser.
● live · /binary-diff
TOTP Generator
Paste a base32 secret or an otpauth:// URI and get the rolling six-digit code with a countdown ring — computed in your browser, never sent anywhere.
● live · /totp-generator
Online Ruler
A ruler on your screen that is actually the right size — calibrate with a credit card, then trust the millimetres.
● live · /online-ruler
Bulk Rename
Pick a folder on your disk, stack up rename rules, preview every old name against its new one, then apply in place — from a web page, with nothing uploaded.
● live · /bulk-rename
Duplicate File Finder
Walk a folder, group files by size, hash only the candidates, and delete the copies you choose — locally, and knowing that deleted really means deleted.
● live · /duplicate-finder
VCF to CSV Converter
Turn a .vcf contact export into a CSV that Excel opens cleanly — and back again. Your contact book never leaves the browser.
● live · /vcf-to-csv
ICS Viewer
Read an .ics calendar file: every event laid out as a list, a month view, and a CSV you can open in a spreadsheet. The file never leaves your browser.
● live · /ics-viewer
MSG Viewer
Read a .msg file someone sent you without installing Outlook: the header, both bodies and every attachment, downloadable. The file never leaves your browser.
● live · /msg-viewer
EML Viewer
Read a raw .eml message without a mail client: the whole header block, both bodies and every attachment, downloadable. The file never leaves your browser.
● live · /eml-viewer
CSV Explorer
Open the CSV Excel refuses — gigabytes, millions of rows — and browse, sort, filter and query it. The file is read off your disk and never uploaded.
● live · /csv-explorer
Device Transfer
Files and whole folders straight from one device to another, over a link the two of them make between themselves.
● live · /device-transfer
Voice Notes
Record microphone or meeting audio with live transcripts and translation — 100% private.
● live · /voice-notes
HLS / M3U8 Player
Paste an m3u8 URL, watch it play — and find out exactly why it does not.
● live · /hls-player
ELF Inspector
Open an ELF, read every structure — the binary never leaves this tab.
● live · /elf-inspector
Encrypt File
Password-encrypt a file in this tab — AES-256-GCM as compact JWE, nothing uploaded.
● live · /encrypt-file
Folder Hash
Walk a folder, write a standard SHA256SUMS file, or drop a checksum file and list matched, mismatched, missing and extra paths — locally.
● live · /folder-hash
Create ZIP
Pick files or a folder, stream a ZIP to disk on Chromium, or download a size-capped archive — locally, nothing uploaded.
● live · /zip-create
Folder Compare
Pick two folders and list only-in-A, only-in-B, and files whose contents differ — size first, then streaming SHA-256, locally.
● live · /folder-compare
Folder Size
Pick a folder and see where the bytes went — a treemap, the largest files, and an extension breakdown. Read-only, nothing uploaded.
● live · /folder-size
Barcode Scanner
Scan barcodes with your camera online: real-time detection, instant inventory counts, editable names, and CSV export.
● live · /barcode-scanner
Clipboard Inspector
Clipboard viewer — every MIME type, raw HTML, hex dump. Local, on a click, then gone.
● live · /clipboard-inspector
HTTP Status Code Reference
What each HTTP status code means — and what the front end, the back end and the visitor each do about it.
● live · /http-status
Port Number Reference
What runs on a port, whether it belongs on the internet, and how to find the process holding it.
● live · /port
Remove PDF Metadata
Open a PDF, see every Info dict field and the XMP stream, then strip what you don't want to keep — in this tab, nothing uploaded.
● live · /pdf-metadata