Tutorials & Guides
In-depth tool tutorials, technical explanations, and best practice guides
Complete Guide to SQL Formatting: Beautify, Minify, and Debug Tips
Explains why SQL formatting matters, keyword casing conventions, indentation styles, strategies for complex queries, and common SQL debugging scenarios.
Complete Guide to PDF to Images: Best Practices for Page-by-Page PNG/JPG Export
Explains how PDF-to-image conversion works, resolution choices, batch export tips, and workflows combining compression, OCR, and other tools after conversion.
Complete Guide to Text Diff: Use Cases and Tips
Explains how text Diff works, Side-by-Side vs Unified views, practical tips for code review and document proofreading, and structured comparison with JSON Diff.
Complete Guide to Timestamp Conversion: Unix Time, Time Zones, and Date Math
Explains Unix timestamp principles, seconds vs milliseconds, time zone handling, Cron expressions, and practical conversion tips for everyday developer debugging.
Complete Guide to URL Encoding: Percent-Encoding Principles and Practice
From URL structure to percent-encoding rules—explains the difference between encodeURIComponent and encodeURI, and how to handle Chinese parameters, special characters, and internationalized domain names correctly.
YAML/JSON Config Conversion Guide: Essential for DevOps and Development
Covers YAML vs JSON syntax differences, conversion pitfalls, and practical tips for Docker Compose, Kubernetes, GitHub Actions, and other config workflows.
Complete Guide to Hashing and Encryption: Using MD5, SHA256, and AES Correctly
From hash functions to symmetric and asymmetric encryption—covers MD5, SHA256, HMAC, and AES: how they work, when to use them, and common security mistakes to avoid.
Complete Guide to Image Format Conversion: PNG, JPG, WebP, and AVIF
Compares PNG, JPEG, WebP, AVIF, GIF, and other popular formats—their strengths, trade-offs, and when to use each—and shows how to convert quickly with an online tool.
Complete Guide to PDF Compression: Smaller Files Without Sacrificing Readability
Explains how PDF compression works, quality vs. size trade-offs, and how to shrink a 50MB PDF to 5MB with an online tool while keeping text sharp and readable.
Complete Guide to Splitting PDFs: Extract, Divide, and Fine-Grained Page Control
Covers 3 PDF splitting methods—split by page, extract ranges, and batch division—plus how to combine split with merge, compress, and other tools for complex document workflows.
Cron Expression Guide: Crontab Syntax Explained
Learn 5-field cron syntax with examples. Parse expressions to plain language with our free tool.
HEIC to JPG Guide: Convert iPhone Photos Online Free
Step-by-step guide to convert HEIC/HEIF iPhone photos to JPG in your browser. Local processing, free, no registration. Includes batch conversion, quality notes, and FAQ.
Image OCR Guide
Extract text from photos with browser-local OCR.
Image Resize Guide
Resize images by pixels or percentage locally.
Images to PDF Guide
Combine JPG/PNG images into one PDF locally.
Markdown Formatting Guide: Write and Preview in One Place
A quick Markdown syntax reference — headings, lists, code blocks, tables — paired with an online live preview tool.
MOV to MP4 Guide: Convert iPhone Videos Online
Convert MOV/QuickTime videos to MP4 in your browser with FFmpeg. Free, local processing.
Password Generator Guide
Create strong random passwords and tokens securely.
PDF Decrypt Guide: Remove PDF Password Online
Remove open/permission passwords when you know the original. Local browser processing.
PDF Encryption Guide: Password Protect PDFs Online
Add open and permission passwords to PDFs locally in your browser. Free, no upload.