# ZeroUtil

> Free online browser-based utility tools for developers and everyday users.
> 50+ tools run entirely in your browser - no signup, no install required.

## Tools

- [QR Code Reader](https://zeroutil.com/tools/qr-code-reader/) : Scan and decode QR codes from any image online - upload a photo, screenshot or saved picture and read the QR contents instantly in your browser.
- [Percentage Calculator](https://zeroutil.com/tools/percentage-calculator/) : Calculate percentages: X% of Y, percentage increase/decrease, and more.
- [AES-256 Encrypt / Decrypt Online - Free, In-Browser](https://zeroutil.com/tools/aes-encrypt-decrypt/) : Encrypt and decrypt text with AES-128, AES-192, or AES-256 in GCM, CBC, or CTR mode. PBKDF2 key derivation, entirely in your browser.
- [Barcode Reader](https://zeroutil.com/tools/barcode-reader/) : Free online barcode reader — upload an image to scan and decode barcodes. Supports EAN, UPC, Code 128, QR and more.
- [Audio Waveform Generator](https://zeroutil.com/tools/audio-waveform-generator/) : Generate a SoundCloud-style waveform image from any audio file. Decoded in your browser, exported as PNG or SVG.
- [QR Code Generator](https://zeroutil.com/tools/qr-code-generator/) : Generate QR codes for URLs, text, email, phone and WiFi.
- [CS2 Voice Comms Calculator](https://zeroutil.com/tools/cs2-voice-comms-calculator/) : Hear specific players in a CS2 or FACEIT demo - upload it to auto-fill players and get the tv_listen_voice_indices commands.
- [Readability Checker](https://zeroutil.com/tools/readability-score/) : Free reading level checker and writing grade level analyzer. Flesch-Kincaid, Flesch Reading Ease, Gunning Fog and Coleman-Liau scores in one place.
- [Base64 to Image Converter](https://zeroutil.com/tools/base64-to-image/) : Decode a Base64 string or data URL back into a viewable image and download it as PNG, JPG, WebP or GIF. Runs in your browser.
- [Base64 Encoder & Decoder](https://zeroutil.com/tools/base64-encode-decode/) : Encode UTF-8 text to Base64 online or decode Base64 back to UTF-8 and plain text. Runs in your browser with no upload.
- [Energy Converter](https://zeroutil.com/tools/energy-converter/) : Convert between joules, megajoules, calories, kilocalories, BTU, therms, watt-hours, kilowatt-hours and electronvolts.
- [Age Calculator](https://zeroutil.com/tools/age-calculator/) : Calculate exact age in years, months and days from a birthdate.
- [Date Difference Calculator](https://zeroutil.com/tools/date-difference-calculator/) : Calculate the exact difference between two dates in years, months, days, weeks, hours and minutes.
- [Color Picker](https://zeroutil.com/tools/color-picker/) : Pick colors visually and get HEX, RGB, and HSL values.
- [Basic Auth Header Generator](https://zeroutil.com/tools/basic-auth-header-generator/) : Create HTTP Basic Authentication headers from a username and password or API token.
- [Video Cropper](https://zeroutil.com/tools/video-cropper/) : Crop MP4, WebM, MOV and MKV videos to a rectangle or aspect preset (16:9, 9:16, 1:1, 4:3). Server-side FFmpeg, no signup. Files auto-deleted after 15 minutes.
- [Business Days Calculator](https://zeroutil.com/tools/business-days-calculator/) : Count business days between two dates excluding weekends and custom holidays.
- [Moving Box Calculator](https://zeroutil.com/tools/moving-box-calculator/) : Estimate moving boxes needed by room type with breakdown by small, medium and large sizes.
- [Salary / Hourly Rate Calculator](https://zeroutil.com/tools/salary-calculator/) : Convert between annual salary, monthly, weekly, daily and hourly pay rates.
- [Fortune Cookie](https://zeroutil.com/tools/fortune-cookie/) : Open a virtual fortune cookie to reveal a random fortune with lucky numbers. 50+ unique fortunes.
- [Prime Number Checker](https://zeroutil.com/tools/prime-number-checker/) : Check if a number is prime and find all primes up to any limit.
- [CSS Clip Path Generator](https://zeroutil.com/tools/css-clip-path-generator/) : Create CSS clip-path shapes with visual editing and presets. Clip-path maker and CSS shape generator in one tool.
- [CS2 Sensitivity Converter](https://zeroutil.com/tools/cs2-sensitivity-converter/) : Convert mouse sensitivity between CS2, Valorant, Apex and more, with eDPI and cm/360.
- [Word Counter](https://zeroutil.com/tools/word-counter/) : Count words, characters, sentences, paragraphs and estimate reading time.
- [Image Vectorizer](https://zeroutil.com/tools/image-vectorizer/) : Convert PNG, JPG, WebP, GIF or BMP images to scalable SVG vector format directly in your browser.
- [PDF Compressor](https://zeroutil.com/tools/pdf-compressor/) : Compress PDFs with Ghostscript image downsampling. Pick a quality preset. Files auto-deleted after 15 minutes.
- [CS2 Crosshair Code Decoder](https://zeroutil.com/tools/cs2-crosshair-code/) : Decode a CSGO-xxxxx crosshair share code into cl_crosshair console commands.
- [Flashcard Maker](https://zeroutil.com/tools/flashcard-maker/) : Create and study flashcards with front/back content, shuffle, and navigation.
- [Morse Code Translator](https://zeroutil.com/tools/morse-code-translator/) : Translate text to Morse code and Morse code to text.
- [Pressure Converter](https://zeroutil.com/tools/pressure-converter/) : Convert between pascals, kilopascals, bar, atmospheres, PSI, mmHg and torr.
- [Markdown to HTML](https://zeroutil.com/tools/markdown-to-html/) : Convert Markdown to HTML with live preview.
- [Fuel Economy Converter](https://zeroutil.com/tools/fuel-economy-converter/) : Convert between MPG (US), MPG (UK), L/100km and km/L with inverse relationship handling.
- [Aesthetic Text Generator](https://zeroutil.com/tools/aesthetic-text-generator/) : Transform text into vaporwave, upside down, small caps, bold, italic, strikethrough, bubble, and square Unicode styles.
- [PBKDF2 Hash Generator](https://zeroutil.com/tools/pbkdf2-hash-generator/) : Derive cryptographic keys from passwords using PBKDF2 with configurable iterations, salt and hash function.
- [ASCII Art Generator](https://zeroutil.com/tools/ascii-art-generator/) : Convert text to large block-letter ASCII art. Supports A-Z, 0-9, and basic punctuation.
- [Video Reverser](https://zeroutil.com/tools/video-reverser/) : Reverse an MP4, WebM, MOV or MKV video and its audio with one click. Server-side FFmpeg handles the full re-encode. Files auto-deleted after 15 minutes.
- [Voice Recorder](https://zeroutil.com/tools/voice-recorder/) : Record voice memos directly in your browser. The audio never leaves your device - no upload, no signup.
- [Random Quote Generator](https://zeroutil.com/tools/random-quote-generator/) : Generate random inspirational, funny, motivational, and wisdom quotes from a curated collection of 50+ quotes.
- [SteamID Converter](https://zeroutil.com/tools/steamid-converter/) : Convert between SteamID64, STEAM_0:Y:Z, SteamID3 [U:1:W], account ID and profile URL.
- [Bulk QR Code Generator](https://zeroutil.com/tools/bulk-qr-code-generator/) : Generate multiple QR codes at once from a list of URLs or text.
- [World Clock](https://zeroutil.com/tools/world-clock/) : Live-updating clocks for multiple timezones. Add and remove cities to build your custom dashboard.
- [Random String Generator](https://zeroutil.com/tools/random-string-generator/) : Generate random strings with configurable length and character set.
- [Image Metadata Viewer](https://zeroutil.com/tools/image-metadata-viewer/) : View file info, dimensions, aspect ratio, and basic EXIF data from any image.
- [Fancy Text Generator](https://zeroutil.com/tools/fancy-text-generator/) : Generate stylish text with bubbles, squares, upside down and more for social media.
- [Remove Duplicate Lines](https://zeroutil.com/tools/remove-duplicate-lines/) : Remove duplicate lines from text with case-sensitive and sorting options.
- [Notes Scratchpad](https://zeroutil.com/tools/notes-scratchpad/) : Simple persistent notepad with auto-save, word count, and local storage.
- [Video Trimmer](https://zeroutil.com/tools/video-trimmer/) : Cut a section from MP4, WebM or MOV videos. Stream-copy is fast and lossless.
- [JSON Dialect Detector](https://zeroutil.com/tools/json-dialect-detector/) : Tell whether a file is JSON, JSONC or JSON5 - and convert it to strict JSON.
- [GIF Maker](https://zeroutil.com/tools/gif-maker/) : Turn multiple images into an animated GIF with custom frame delay.
- [Random Color Generator](https://zeroutil.com/tools/random-color-generator/) : Generate random colors with HEX, RGB and HSL values. Random color picker, colour randomizer and 5-color palette builder with history.

## Guides

- [Base64 Explained: What It Is, Why It Exists, and When Not to Use It](https://zeroutil.com/blog/base64-explained/) : What Base64 does to your bytes, the three variants that produce most decode failures, and the places it still earns its keep.
- [Client-Side Image Compression: What Happens in the Browser](https://zeroutil.com/blog/client-side-image-compression/) : The real pipeline behind Canvas, OffscreenCanvas and WebCodecs, which formats a browser will and will not encode, and when you still need a server.
- [How to Compare a Design to Your Build, Pixel by Pixel](https://zeroutil.com/blog/compare-design-to-build-pixel-by-pixel/) : Overlay the mockup on the live page and let difference blending find the drift. The method, what each blend mode is for, and what the tools here cost.
- [Why You Can't Hear Voice in Your CS2 Demo (Fixes)](https://zeroutil.com/blog/cs2-cant-hear-voice-demo/) : Can't hear voice comms in a CS2 or FACEIT demo? The real causes - no voice in MM/Premier demos, unset tv_listen_voice_indices, reset commands - and fixes.
- [What Importing a CS2 Crosshair Code Actually Changes](https://zeroutil.com/blog/cs2-crosshair-code-what-changes/) : A CS2 crosshair share code writes 21 cl_crosshair variables, truncates a few, and skips your scoped crosshair. Why an imported one can still look off.
- [CS2 Crosshair Share Codes: What Those 25 Characters Hold](https://zeroutil.com/blog/cs2-crosshair-share-code-format/) : Twenty-five characters hold eighteen bytes, twenty-one console commands, and forty-one bits that carry nothing at all. Every field, decoded and measured.
- [CS2 Demo Ticks: Tick to Time, and demo_gototick](https://zeroutil.com/blog/cs2-demo-tick-to-time/) : A demo tick over the demo's tick rate is a timestamp. What catches people is which tick rate, which counter the number came from, and where demo_gototick lands.
- [How to Hear the Enemy Team's Voice in a CS2 Demo](https://zeroutil.com/blog/cs2-hear-enemy-team-voice-demo/) : Whether you can hear the enemy in a CS2 demo depends on what the server recorded, not on your console. Which demos carry it, and the mask for one side.
- [How to Hear Voice Comms in a CS2 Demo](https://zeroutil.com/blog/cs2-hear-one-player-voice-demo/) : Hear voice comms in a CS2 demo with tv_listen_voice_indices: which demos record voice, how the slot bitmask works, and how to isolate one player or a side.
- [How to Hear Voice Comms in a FACEIT Demo (CS2)](https://zeroutil.com/blog/cs2-hear-voice-comms-demos/) : FACEIT records both teams' voice, but only in one of the two demos a match leaves you. Which file to open, the three FACEIT commands, and the slot bitmask.
- [Every Way to Hear FACEIT Demo Voice Comms, Compared](https://zeroutil.com/blog/faceit-demo-voice-comms-tools-compared/) : Console commands, a web calculator, CS Demo Manager, a voice extractor and extensions: what each does for FACEIT demo voice and what it leaves to you.
- [JSON vs JSON5 vs JSONC: What Each Parser Actually Accepts](https://zeroutil.com/blog/json-vs-json5-vs-jsonc/) : JSON, JSON5 and JSONC share a file extension but not a definition of valid. Tested against real parsers, including one library that disagrees with itself.
- [Password Strength: What Length and Character Sets Buy You](https://zeroutil.com/blog/password-strength-2026/) : Entropy done honestly, NIST's current 15-character floor, and measured GPU cracking speeds showing the hash function matters more than the extra characters.
- [The PDF Tools Everyone Should Know](https://zeroutil.com/blog/pdf-tools-guide/) : A hands-on walkthrough of the PDF tasks you hit every week: compress, merge, split, convert, OCR, and sign, with steps you can follow right now.
- [Percentage Points vs Percent: 5 Mistakes That Change the Answer](https://zeroutil.com/blog/percentages-common-mistakes/) : A rate that falls 1% and one that falls 1 percentage point are ten times apart. That confusion, plus four more that quietly turn a correct number wrong.
- [Converting Mouse Sensitivity Between Games Is One Division](https://zeroutil.com/blog/sensitivity-conversion-yaw-constants/) : Every cross-game sensitivity converter runs on one division and seven numbers. Where they come from, and four places the math stops matching how aim feels.
- [SteamID64, STEAM_0 and SteamID3 Share One Account Number](https://zeroutil.com/blog/steamid-account-number-bit-layout/) : STEAM_0:Y:Z, SteamID3 and SteamID64 all read one 32-bit account number. How Valve's 64-bit layout works, and what it cannot derive: a vanity URL.
- [Why tsconfig.json Allows Comments and package.json Does Not](https://zeroutil.com/blog/tsconfig-json-comments-jsonc/) : Both files end in .json. One accepts comments and trailing commas, the other throws. The difference is not the extension - it is which parser reads the file.

## Translations

- [Извлечение войса из демок CS2](https://zeroutil.com/ru/tools/cs2-demo-voice-extractor/) (Русский) : Скачайте голос каждого игрока из демки CS2 или FACEIT отдельным аудиофайлом и посмотрите, кто и когда говорил, по раундам.
- [Калькулятор войса для демок CS2](https://zeroutil.com/ru/tools/cs2-voice-comms-calculator/) (Русский) : Слушайте нужных игроков в демке CS2 или FACEIT - загрузите демку, игроки подставятся сами, а вы получите команды tv_listen_voice_indices.
- [Почему в демке CS2 не слышно войс (и как это исправить)](https://zeroutil.com/ru/blog/cs2-cant-hear-voice-demo/) (Русский) : Не слышно войс в демке CS2 или FACEIT? Реальные причины - нет голоса в демках ММ/Premier, не задан tv_listen_voice_indices, сброс команд - и решения.
- [Тики в демках CS2: перевод тика во время и demo_gototick](https://zeroutil.com/ru/blog/cs2-demo-tick-to-time/) (Русский) : Тик демки, деленный на тикрейт, дает время. Ошибаются в другом: какой тикрейт, из какого счетчика взят номер и куда попадает demo_gototick.
- [Как услышать войс вражеской команды в демке CS2](https://zeroutil.com/ru/blog/cs2-hear-enemy-team-voice-demo/) (Русский) : Услышите ли вы врагов в демке CS2, решает то, что записал сервер, а не ваша консоль. В каких демках есть их голос и какая маска нужна для одной стороны.
- [Как услышать войс в демке CS2](https://zeroutil.com/ru/blog/cs2-hear-one-player-voice-demo/) (Русский) : Войс в демке CS2 через tv_listen_voice_indices: в каких демках есть голос, как работает маска слотов и как выделить одного игрока или сторону.
- [Как услышать войс в демке FACEIT (CS2)](https://zeroutil.com/ru/blog/cs2-hear-voice-comms-demos/) (Русский) : FACEIT пишет голос обеих команд, но только в одной из двух демок матча. Какой файл открыть, три команды от FACEIT и битовая маска слотов.
- [Все способы услышать войс в демке FACEIT: сравнение](https://zeroutil.com/ru/blog/faceit-demo-voice-comms-tools-compared/) (Русский) : Консольные команды, веб-калькулятор, CS Demo Manager, экстрактор голоса и расширения: что каждый делает с войсом демок FACEIT и что оставляет вам.

## About

- [About ZeroUtil](https://zeroutil.com/about/) : Mission, tool philosophy, and privacy-first approach
- [Methodology](https://zeroutil.com/methodology/) : How we build, test, and maintain our tools