Port Scanner Online — Check Open Ports and Network Connectivity
Learn what TCP/UDP ports are, the most common port numbers and their services, how to interpret port scan results, and how to check open ports on any server for free online.
131 閲覧
Tools
A collection of online utilities to help you work efficiently.
77 記事
Email Deliverability Tools — SPF, DKIM & DMARC Checker Guide
Learn how SPF, DKIM, and DMARC email authentication protocols work, how to configure them correctly, and how to use free online tools to verify your domain's email setup and improve deliverability.
151 閲覧
Base Converter Online — Binary, Hex, Decimal & Octal Conversion
Learn how binary, octal, decimal, and hexadecimal number systems work, how to convert between them, and their practical uses in programming and computer science.
144 閲覧
Text Case Converter — camelCase, snake_case, kebab-case & More
Learn the naming conventions used in programming — camelCase, snake_case, PascalCase, kebab-case — when each is used, and how to convert between them instantly online for free.
137 閲覧
URL Encoder & Decoder — Percent-Encoding Complete Guide
Learn how URL encoding (percent-encoding) works, which characters must be encoded, the difference between encodeURI and encodeURIComponent, and how to encode or decode URLs online for free.
184 閲覧
TOTP Generator — How Two-Factor Authentication (2FA) Codes Work
Learn how TOTP (Time-based One-Time Password) works, why it's more secure than SMS codes, and how to test your 2FA implementation with a free online TOTP generator.
158 閲覧
Barcode Generator Online — Create Code 128, EAN-13, UPC-A & More
Learn the difference between barcode formats (Code 128, EAN-13, UPC-A, QR Code), how to choose the right one, and how to generate printable barcodes online for free.
165 閲覧
GIF Splitter — Extract Frames from Animated GIFs Online
Learn how to split a GIF into individual frames online, understand GIF frame delay and structure, and download extracted frames as PNG files — free, no upload.
163 閲覧
Checksum & CRC Calculator — Verify File Integrity with MD5, SHA-256 & CRC32
Learn how checksums and CRC work, when to use MD5 vs SHA-256 vs CRC32, and how to verify file integrity online for free to detect corruption or tampering.
122 閲覧
Exchange Rate Converter — Real-Time Currency Conversion Online
Learn what drives exchange rates, how to find the best rates for travel and transfers, and convert any currency pair instantly with a free online exchange rate calculator.
178 閲覧
Car Insurance Calculator — 8 Factors That Affect Your Premium
Learn what drives car insurance premiums, the main coverage types and what they protect, and how to estimate your auto insurance cost with a free online calculator.
42 閲覧
LTV Calculator — How to Calculate Customer Lifetime Value
Learn how to calculate LTV (Customer Lifetime Value), the LTV/CAC ratio, and how to use these metrics to evaluate acquisition strategy and growth sustainability.
41 閲覧
Color Converter Online — HEX to RGB, RGB to HSL & More
Learn the difference between HEX, RGB, and HSL color formats, when to use each, and how to convert between them instantly online for free. Essential for web designers and developers.
59 閲覧
EXIF Viewer — Read Hidden Photo Metadata, GPS Location and Camera Settings
Learn what EXIF data is, what information is hidden in your photos (including GPS location), and how to view image metadata online for free. Includes important privacy warnings.
46 閲覧
SaaS Churn Calculator — MRR Churn, Customer Churn & NRR
Learn how to calculate SaaS churn rate, MRR churn, and net revenue retention (NRR). Free online calculator with industry benchmarks and strategies to reduce churn.
34 閲覧
Profit Margin Calculator — Gross Margin, Net Margin & Markup
Learn the difference between gross margin, net margin, and markup. Calculate profit margins for any product or business with the free online profit margin calculator.
52 閲覧
JWT Debugger — Decode and Verify JSON Web Tokens Online
Learn JWT structure, how signing works, common security vulnerabilities, and how to decode and verify JWT tokens for free online. Essential tool for developers.
39 閲覧
Break-Even Calculator — Find Your Business Break-Even Point
Learn the break-even formula, the difference between fixed and variable costs, and how to use break-even analysis for pricing, expansion, and investment decisions.
36 閲覧
Net Worth Calculator — Calculate and Grow Your Personal Net Worth
Learn how to calculate net worth, what counts as assets and liabilities, and how to track your financial health over time. Free online net worth calculator included.
34 閲覧
Unix Timestamp Converter Online — Convert Between Timestamp and Date
Learn what Unix timestamps are, why developers use them, and how to convert between timestamps and human-readable dates in multiple time zones. Free online tool with code examples.
31 閲覧