MeTool Blog
Scenario-driven guides, comparisons and technical deep-dives that help you find and get the most out of the right online tool.
Solutions
Start from a real-life or work pain point and solve it step by step with the right tool.
Advanced Markdown: Math, Diagrams, Collapsible Blocks, and More
Beyond headings, lists, and tables—how do you write math, draw flowcharts in text, collapse long sections, or add sub/superscripts in Markdown? This guide covers six advanced patterns with source plus real render screenshots, notes on renderer support, and examples you can paste into an online editor.
How Do You Write Markdown? 10 High-Frequency Patterns to Learn by Doing
New to Markdown and stuck on #, *, and backticks? This guide covers only the ten most-used patterns—headings, bold/italic, lists, task lists, links and images, code blocks, quotes, tables, and horizontal rules—each with source plus rendered examples you can paste into an online editor.
How to Play Reversi? Flips, Legal Moves, and Endgame
An illustrated guide—with teaching demo videos—to Reversi (Othello) rules: the opening four discs, how sandwich flips work, why a move must flip at least one disc, multi-direction flips, passing when you have no move, scoring by disc count, plus beginner tips on corners and X-squares.
Need a “Confidential” Watermark on a Contract PDF—What Actually Works?
Before you share contracts, drafts, or course packs, a visible Confidential / Draft watermark helps. This article covers what visible watermarks prevent, when to use text vs a logo, why CJK glyphs go missing, how to choose tiling and page ranges, and what watermarks cannot do.
Chinese in LaTeX Comes Out Blank or Font Not Found? Check Your Engine First
Most CJK LaTeX errors aren't a package problem, they're an engine problem: pdfLaTeX's font model physically cannot hold thousands of Han characters. How the three engines differ, which ctex fontset to pick, and what font not found and ctexart.cls not found actually mean.
LaTeX Showing ?? and Wrong Page Numbers? You Only Compiled Once
The ?? in your PDF and the off-by-one table of contents aren't syntax errors — they mean LaTeX's multi-pass cycle hasn't finished. How .aux and .toc work, how many passes you need, why BibTeX takes four steps, and how to read the log to know you're done.
Comparisons
Side-by-side comparisons of approaches, tools and formats to help you choose.
AirDrop, Messaging Apps, Cloud, or LAN Transfer: How to Choose
AirDrop, messaging file transfer, cloud storage, and LAN direct transfer are not replacements for each other—they fit different scenes. This article compares cross-platform support, speed, quality, privacy, and account requirements, with a decision framework.
What Does Image Compression Remove? Choosing JPG, PNG, WebP, and AVIF
The same image as JPG, PNG, WebP, or AVIF can differ in size by several times. This article explains lossy vs. lossless, what each format excels at, and a decision table for screenshots, photos, and illustrations.
Choosing Invisible Watermarking: Frequency-Domain vs. SynthID vs. C2PA
Invisible watermarks for anti-theft and provenance differ widely: classic frequency-domain blind watermarks, deep-learning watermarks (SynthID/Pixel Seal), and C2PA metadata signatures. This comparison covers robustness, customization, and use cases.
Choosing Perler Bead Pattern Tools: Color Charts, Kit Alignment, and Editing
Converting images to fuse-bead patterns differs less in 'can it convert' than in whether exported color codes match beads you actually own. This compares MeTool, Pixelbead, and 拼豆酱 on MARD charts, kit alignment, brush editing, and color counts.
Choosing Screen Recording Zoom Tools: Screen Studio, Cap, and Online Editors Compared
Viewers can't find the action in screen recordings—dynamic focus (auto zoom) is the fix. This compares Screen Studio, OpenScreen, Cap, CapCut/iMovie, and online editors on zoom, platform, price, and editing workflow.
Overleaf, Local TeX, or Online Tools? A Decision Guide for Writing LaTeX
Overleaf, local TeX Live, and lightweight online tools are not ranked good vs bad—they fit different tasks. This article compares collaboration, privacy, packages, offline use, and cost, with a decision framework.
Tech Deep-Dives
How the tools work under the hood — principles, implementation and limits.
What Are Gomoku Forbidden Moves? Double-Three, Double-Four, Overline
A clear guide to Renju’s three black-only fouls—double-three, double-four, and overline—with diagrams showing why one move that creates two threats loses, how that differs from freestyle Gomoku and an exact five-in-a-row win, plus how to practice in the browser.
How Does a Go AI Choose Moves? An Intro to MCTS
Why Go needs Monte Carlo Tree Search, the four steps of selection/expansion/simulation/backprop, and real engineering trade-offs under browser simulation budgets: UCB1 constants, visit distributions, opening narrowing, and eye-filling in the endgame.
Diagram-as-Code: How Text Becomes Graphics, Engines, and Limits
How do Mermaid, PlantUML, and Graphviz turn text descriptions into diagrams? This article covers the parse–layout–render pipeline, trade-offs between engines, and where automatic layout stops working.
Don't Store Passwords with MD5: Hash, Salt, and Password Hashing Explained
MD5 and SHA-256 are hash algorithms, but using them directly for passwords is wrong. This article clarifies hash vs. salt vs. password hashing (bcrypt/Argon2), and why file checksums use SHA-256 while passwords need slow hashes.
Can Blind Watermarks Survive Screenshot, Compression, and Rotation?
Blind watermarks hide information in image frequency domain—invisible to the eye. But do they survive WeChat compression, screenshots, and rotation? This article covers spatial vs. frequency domain, DCT/DWT, geometric attack resistance, and limits.
Why Is the 3D Model in My Web Page So Laggy? Decimation, Vertex Welding, and Texture Compression
Smooth in Blender, sluggish on the web with long loads. This article covers triangle count, duplicate vertices, and texture size—the principles, tradeoffs, and limits of Web 3D optimization.
One Markdown Draft, Many Channels: WeChat, Xiaohongshu, and PDF
Same content for WeChat, Xiaohongshu, and PDF means reformatting on every platform. This article walks a real publish pipeline—write once in .md, then convert for WeChat, Xiaohongshu cards, and PDF delivery—with pitfalls at each step.
From Formulas to Submission: A No-Install LaTeX Paper Pipeline
Writing formulas, editing with preview, exporting PDF, compressing, and sharing with advisors—each step has its own pitfalls. This article walks through a real submission workflow: what each step solves and how to avoid common mistakes.