UD5 Toolkit
File Type from Magic Bytes Detector - Online Identify Unknown Files
Drop a file and see its detected type based on the first bytes (magic number). Identifies hundreds of formats. Local.
File Extension Database Lookup - Online Search Type
File Extension Lookup
Instant details for any file extension â type, MIME, programs & more.
Enter a file extension with or without the dot.
Popular Extensions
| Extension | Type | MIME | Programs |
|---|
Click any row to see full details.
Frequently Asked Questions
A file extension is the suffix at the end of a filename (e.g.,
.txt, .jpg) that indicates the file type and helps the operating system determine which application to use to open it.
You can use our lookup tool to identify the file type. Once you know the format, you can install the recommended program or use a universal file viewer like VLC or File Viewer Plus.
Yes, but simply renaming the extension does not convert the file. It might become unreadable. For example, changing
document.docx to document.pdf won't create a PDF. Use proper conversion software instead.
MIME (Multipurpose Internet Mail Extensions) type is a standard way of identifying files on the Internet according to their nature and format. For example,
text/html for HTML files and image/png for PNG images.
Common extensions include
.pdf (documents), .jpg/.png (images), .mp3 (audio), .mp4 (video), .zip (compressed archive), .html (web pages), and .exe (executable). Browse our table above for more.
Acronym Expander - Online Find What It Stands For
Enter an acronym and see its most common full forms. Static dictionary. No internet needed after load.
File MIME Type & Magic Bytes Detector - Online
Drop a file to see its MIME type and the first few magic bytes (hex and ASCII). No upload, works instantly.
Headlight Bulb Lookup & CrossâReference â Online Bulb Finder
Enter your vehicle to find the correct headlight, fog, and interior bulb part numbers. Prints a list.
SD Card Formatter Types - Online File System Guide
Understand which file system to choose for your SD card based on capacity and device. A quick guide, no actual formatting.
Structured Data Testing Tool - Online Validate Rich Results
Paste your JSONâLD or Microdata and test it against Google's Rich Results criteria. Get warnings. Local linter.
Text File Merger - Online Combine Multiple TXT
Upload multiple text files and concatenate them into one, with optional separators. No upload; processed instantly.
Shopping List Builder - Online Categorized Grocery Checklist
Create categorized shopping lists (produce, dairy, meat, etc.). Add items, check them off, and print. Data stored in your browser. Never lose a list.
Baby Name Finder - Online Meaning & Popularity Lookup
Search a database of baby names by origin, meaning, starting letter, or popularity. Save favorites list locally. Purely frontend with no tracking.
Envelope Size Finder â Online Match Paper & Card
Enter the dimensions of your insert and get the correct envelope size (DL, C6, etc.). Quick mail guide.
File Handle API Demo - Online Persistent File Access
Use the File System Access API with file handles for persistent read/write. Learn incremental saving patterns.
PDF Compressor - Online Reduce File Size Locally
Shrink a PDF file size with configurable image quality and object removal. All processing stays in your browser.
Digital Photo Album â Online Arrange & Caption Memories
Create a simple grid or carousel album with local images and captions. Export as printable PDF. Private.
Expense Tracker - Online Simple Budget & Spend Logger
Track personal expenses and categorize spending. Interactive charts show where your money goes. All financial data remains in your browser only.
Baby Name Meanings - Online Quick Meaning & Origin Lookup
Search a name and see its meaning, origin, and popularity. Static name database. For parentsâtoâbe.
Bulk Text Line Sorter - Online AâZ & ZâA
Sort hundreds of lines alphabetically, reverse alphabetically, or by length. Deduplicate option. All local.
Text Similarity Checker - Online Cosine & Jaccard
Paste two texts and see cosine and Jaccard similarity scores. Understand how close two documents are. All local math.
Text Language Detector - Online Identify Language from Input
Paste text and detect its language (70+ languages) using a simple character n-gram model implemented in JavaScript. No server communication.
ISBN Validator - Online Check ISBNâ10 & ISBNâ13
Validate ISBNâ10 and ISBNâ13 numbers and compute their check digits. Useful for booksellers and libraries. All local.
File Name Sanitizer - Online Remove Invalid Characters
Paste a string and get a clean, safe file name by replacing forbidden characters. Works for Windows, Mac, Linux.
i18n JSON to CSV Converter - Online Flatten Translation Files
Convert nested JSON translation files into a flat CSV table for translators. Also reverse back. Local only.
CAA Record Generator - Online DNS Certification Authority
Create a CAA DNS record to specify which certificate authorities can issue SSL certs for your domain. Prevent misâissuance.
Baby Name Compatibility Test â Online Fun Sibling Pair
Enter two names and get a whimsical compatibility score based on vowels, length, etc. Just for fun.
Pros & Cons List Maker - Online Decision Helper
Create a weighed pros and cons list with a score. Help make tough decisions. Data saved locally.
DNS Propagation Checker - Online Verify Record Status
Query a domain's DNS record against multiple public resolvers (Google, Cloudflare) and see how it propagates. Clientâside fetch.
Text to ASCII Binary - Online Detailed Representation
Shows each character's 7âbit or 8âbit binary representation. Includes space separation. For learning binary encoding.
Focus Order Analyzer - Online Tab Navigation Check
Enter a URL and extract tabâindex order violations and focusable elements. Quick accessibility audit. Clientâside fetch.
Spell with Military Alphabet - Online NATO Encoder
Enter any phrase and see it spelled letter by letter using the NATO phonetic alphabet. Copy ready for radio.
CSS Declaration Sorter â Online Organize Properties
Paste a CSS rule and sort its declarations alphabetically or by box model grouping. Clean up styles.
Ordinal Number Converter - Online 1st, 2nd, 3rd Maker
Turn a cardinal number (23) into its ordinal form (23rd). Supports large numbers. Simple and quick.