全部指南
50 篇指南帮您充分利用免费在线工具 — 分步教程、深度解释、比较和技巧。
如何编码与解码 Base64 — 完全指南
Learn what Base64 encoding is, how it works, when to use it, and how to encode and decode Base64 in your browser —no tools or signup needed.
comparisonBase64 vs Hex 编码：该使用哪一个？
Compare Base64 and Hex encoding across efficiency, readability, use cases, and trade-offs — and learn when to pick each for binary-to-text encoding.
explanation颜色格式详解：HEX、RGB 与 HSL
Understand the three most common web color formats —HEX, RGB, and HSL —how each represents color, when to use which, and how to convert between them.
comparisonCSV vs TSV：该使用哪种分隔符格式？
Compare CSV and TSV across delimiter choice, escaping, compatibility, and use cases — and learn when to pick each for tabular data.
referenceDNS 记录详解：A、AAAA、MX、TXT、CNAME、NS
A complete reference guide to DNS record types —A, AAAA, MX, TXT, CNAME, and NS —with examples, use cases, and how to look them up.
explanation哈希算法详解：MD5、SHA-1、SHA-256、SHA-512
Understand cryptographic hash functions: differences between MD5, SHA-1, SHA-256, and SHA-512, and which to use for integrity checks vs password storage.
how-to如何压缩图片而不损失质量
Step-by-step guide to compressing images (JPEG, PNG, WebP) to reduce file size without visible quality loss using a free browser-based tool.
how-to如何逐步压缩 PDF 文件
Step-by-step guide to compressing PDF files to reduce file size using a free browser-based tool. Learn compression levels and what affects PDF size.
how-to如何在 HEX、RGB 与 HSL 之间转换颜色
Step-by-step guide to converting colors between HEX, RGB, HSL, and other formats using a free browser-based tool. Learn when to use each format.
how-to如何逐步将 CSV 转换为 JSON
Step-by-step guide to converting CSV data to JSON using a free browser-based tool. Learn header handling, nested structures, and common pitfalls.
how-to如何逐步将 Markdown 转换为 HTML
Step-by-step guide to converting Markdown text to HTML using a free browser-based tool. Learn syntax, extensions, and common use cases.
how-to如何逐步在文本与二进制之间转换
Step-by-step guide to converting text to binary (0s and 1s) and decoding binary back to text using a free browser-based tool. Learn ASCII and UTF-8.
how-to如何将 Unix 时间戳转换为可读日期（逐步指南）
Step-by-step guide to converting Unix timestamps (epoch) to human-readable dates and back using a free browser-based tool. Learn seconds vs milliseconds.
how-to如何安全地解码 JWT 令牌并检查声明
Step-by-step guide to decoding JWT (JSON Web Token) tokens and inspecting their header and payload claims using a free browser-based tool. Learn security boundaries.
how-to如何逐步编码与解码 Base64 字符串
Step-by-step guide to encoding text to Base64 and decoding Base64 back to text using a free browser-based tool. No upload, no signup, fully private.
how-to如何逐步编码与解码 URL
Step-by-step guide to URL encoding (percent-encoding) and decoding using a free browser-based tool. Learn why and when to encode URLs.
how-to如何逐步从 PDF 文件中提取文本
Step-by-step guide to extracting text content from a PDF file using a free browser-based tool. Learn scanned vs digital PDFs.
how-to如何逐步格式化与验证 JSON 数据
Step-by-step guide to formatting (beautifying) and validating JSON data using a free browser-based tool. Catch syntax errors, minify, and pretty-print JSON instantly.
how-to如何逐步生成哈希值
Step-by-step guide to generating cryptographic hash values (SHA-256, SHA-1, MD5) using a free browser-based tool. Learn use cases and security tradeoffs.
how-to如何逐步生成安全密码
Step-by-step guide to generating strong, random passwords using a free browser-based tool. Learn password length, character sets, and security best practices.
how-to如何逐步生成 UUID
Step-by-step guide to generating UUIDs (Universally Unique Identifiers) using a free browser-based tool. Learn UUID v4, v1, and when to use each.
how-to如何逐步合并 PDF 文件
Step-by-step guide to merging (combining) multiple PDF files into one using a free browser-based tool. Learn ordering and page ranges.
how-to如何逐步调整图片尺寸
Step-by-step guide to resizing images (change width and height) using a free browser-based tool. Learn aspect ratio, upscaling, and common dimensions.
how-to如何逐步拆分 PDF 文件
Step-by-step guide to splitting a PDF file into multiple parts or extracting specific pages using a free browser-based tool.
how-to如何逐步测试正则表达式
Step-by-step guide to testing and debugging regular expressions using a free browser-based tool. Learn flags, capture groups, and common patterns.
how-to如何使用取色器从任意像素获取颜色
Step-by-step guide to using a color picker to find the exact color (HEX, RGB, HSL) of any pixel in an image or on screen using a free browser-based tool.
explanationJSON 格式化最佳实践：易读、有效且高效
Understand the conventions for formatting JSON: indentation, key ordering, minification, trailing commas, and when to pretty-print vs minify.
explanation理解 JSON：格式化和验证的初学者指南
了解什么是 JSON、其语法规则、常见数据类型，以及如何使用免费在线工具格式化和验证 JSON 数据。
comparisonJSON vs XML：该使用哪种数据格式？
Compare JSON and XML across syntax, verbosity, parsing speed, ecosystem support, and use cases — and learn when to pick each.
comparisonJSON vs YAML：该使用哪种配置格式？
Compare JSON and YAML across readability, features, use cases, and trade-offs — and learn when to pick each for configuration and data interchange.
how-to如何安全地解码 JWT 并检查其声明
Learn the three-part structure of a JSON Web Token, how to decode the header and payload without verifying, and why decoding is not the same as trusting.
comparisonMarkdown vs HTML：内容该使用哪个？
Compare Markdown and HTML across readability, expressiveness, learning curve, use cases, and rendering —and learn when to pick each (or both).
problem-solving密码安全性：如何生成、存储与审计强密码
Solve the most common password security problems: generating strong passwords, hashing them correctly, avoiding reuse, and auditing existing credentials.
comparisonPDF 压缩器 vs 图片压缩器：您需要哪个？
Compare PDF and Image compression across targets, techniques, quality trade-offs, and use cases — and learn which tool to use for your file size problem.
reference正则表达式速查表：语法、标志与常见模式
Complete regex reference: metacharacters, character classes, quantifiers, anchors, groups, flags, and ready-to-use patterns for emails, URLs, and dates.
how-to如何将 Unix 时间戳转换为可读日期
Learn what a Unix timestamp is, how to convert it to a human-readable date and back, and how to handle time zones correctly when working with epoch time.
reference单位换算参考：长度、质量、温度与面积
A complete reference of conversion factors for length, mass/weight, temperature, and area, with exact formulas and worked examples for each.
how-to如何编码与解码 URL — 完全指南
Learn what URL encoding (percent-encoding) is, why it is required, and how to encode and decode URLs in your browser —no signup, fully private.
comparisonUUID v1 vs v4 vs v5：该使用哪个版本？
Compare UUID versions 1, 4, and 5: how each is generated, their trade-offs in uniqueness, ordering, and determinism, and which to pick for your use case.
explanation什么是 Base64 编码？完整说明
A clear explanation of what Base64 encoding is, how it works, its character set, and why it is not encryption.
explanation什么是 CSV？逗号分隔值的完整说明
A clear explanation of what CSV (Comma-Separated Values) is, its syntax rules, common variations, and when to use CSV vs JSON.
explanation什么是哈希？哈希函数的完整说明
A clear explanation of what hashing is, properties of cryptographic hash functions, common algorithms (SHA-256, MD5), and use cases.
explanation什么是 JSON？JavaScript 对象标记法的完整说明
A clear explanation of what JSON (JavaScript Object Notation) is, its syntax, data types, history, and why it replaced XML as the web's data format.
explanation什么是 JWT？JSON Web Token 的完整说明
A clear explanation of what a JWT (JSON Web Token) is, its three-part structure, how it is used for authentication, and security considerations.
explanation什么是 Markdown？轻量标记语言的完整说明
A clear explanation of what Markdown is, its syntax, why it is popular for documentation, and how it converts to HTML.
explanation什么是正则表达式？完整说明
A clear explanation of what a regular expression (regex) is, its syntax, common use cases, and why regex is powerful but hard to read.
explanation什么是 Unix 时间戳？Epoch 时间的完整说明
A clear explanation of what a Unix timestamp is, the Unix epoch, seconds vs milliseconds, and the Year 2038 problem.
explanation什么是 URL 编码？百分比编码的完整说明
A clear explanation of what URL encoding (percent-encoding) is, which characters need encoding, and how it works.
explanation什么是 UUID？通用唯一标识符的完整说明
A clear explanation of what a UUID is, its versions (v1, v4, v5), structure, collision probability, and when to use UUIDs.
how-to如何准确计算字数、字符数与阅读时间
Learn how word and character counts are defined across languages, how to estimate reading time, and how to use a counter to hit limits for essays, tweets, and meta descriptions.