Tools Hub工具库

135 Free Online Tools · 100% Client-Side Privacy135 款实用在线工具 · 100% 浏览器本地运算与隐私保护

Math & Statistics数学与统计计算(32)Developer Tools开发调试工具(28)Unit Converters多功能单位换算(13)Finance & Investment金融理财与投资计算(24)Text Processing文本处理(13)Security & Privacy安全与隐私(5)Office & DocumentsOffice 办公与文档处理(3)Daily Calculators日常计算(4)Color & Design颜色与设计(5)SEO & SiteSEO 与站点(4)Media Files媒体文件(3)Experiments & Fun实验与趣味(1)

Math & Statistics数学与统计计算

Every calculator: scientific calculator, function graphing, percentages, fractions, ratios, summary statistics and linear regression.全部计算工具：科学计算器、函数图像绘制、百分比增减、比例方程、最简分数、统计分析与线性回归。

Scientific Calculator科学计算器

Standard and scientific calculator with variables, history and DEG/RAD modes.标准与科学计算器，支持变量存储、历史记录与角度/弧度切换。

Function Grapher函数图像绘制器

Plot up to 5 functions with zoom, pan and a live value crosshair.同时绘制多达 5 条函数图像，支持平移缩放与十字准星实时取值。

3D Surface Plotter三维函数图像绘制器

Plot z = f(x, y) as a shaded 3D surface you can rotate, zoom and inspect.把 z = f(x, y) 绘制为可旋转缩放的三维曲面，支持等高配色与极值读数。

Percentage Calculator百分比计算器

What is P% of V, N as a percent of V, and value increased or decreased by a percent.快速计算数值的 P% 百分比、占比多少以及按百分比增减后的数值。

Percentage Increase Calculator百分比增减计算器

Percentage change between two values, with absolute change and multiplier.计算两个数值之间的相对增长/下降百分比、绝对差值与变化倍数。

Fraction Calculator分数计算器

Simplify fractions, convert to decimal and percent, and decimals back to exact fractions.分数约分最简式、转小数与百分比，支持小数利用连分数逆向还原为精确分数。

Ratio & Proportion Calculator比例与比例方程计算器

Simplify ratios, solve proportions A:B = C:x, and convert to decimal and percent.化简比值为最简整数比，求解 A:B = C:x 比例方程与小数百分比互转。

Prime Factorization质因数分解

Factor a whole number into primes as 2^3 × 3 × 5, with the divisor count.把一个整数分解为质因数（如 2^3 × 3 × 5），并给出约数个数。

Combinations & Permutations组合与排列计算器

Compute nCr (combinations), nPr (permutations) and n! with exact BigInt results.精确计算组合数 nCr、排列数 nPr 与阶乘 n!，大数使用 BigInt 无溢出。

Descriptive Statistics描述统计与线性回归

Sum, mean, median, mode, min/max and both sample & population standard deviation — plus optional simple linear regression.求和、均值、中位数、众数、极值、样本与总体标准差，并可对 y 关于 x 做一元线性回归。

Pi Calculator (π up to 1,000,000 Digits)圆周率 π 计算器（100 万位高精度）

Compute Pi (π) up to 1,000,000 decimal places using a high-precision Hybrid Engine (Machin & Chudnovsky) with real-time progress and CPU benchmark presets.采用分段混合引擎（低位数 Machin 秒开，1.5 万位以上自动切换 Chudnovsky 超高阶级数与二进制拆分）实时计算圆周率 π 至 100 万位（1,000,000）。

Matrix Calculator (Linear Algebra)矩阵计算器（线性代数）

Perform matrix arithmetic and linear algebra operations: Determinant, Inverse, Trace, Transpose, Addition, and Multiplication.线性代数常用矩阵运算工具：行列式求解、逆矩阵、矩阵的迹、转置矩阵以及矩阵加减与乘法。

Equation, Calculus & Limit Solver方程求解、微积分与极限计算器

Solve quadratic and cubic equations, 2x2 linear systems, calculate numerical derivatives, definite integrals, and function limits (e.g. sin(x)/x as x→0).一元二次与三次方程（含复数根）、二元一次线性方程组求解，以及数值微积分与极限求解（如 sin(x)/x 趋向 0 的极限）。

Complex Numbers Calculator复数计算器（代数与极坐标形式）

Perform complex arithmetic, rectangular to polar Euler form conversion, powers, roots, and complex functions.复数代数运算与极坐标/欧拉形式互转，支持模长辐角、共轭、乘方、开方及复指数对数。

Vector Calculator (2D & 3D)空间向量计算器（2D / 3D）

Calculate 2D and 3D vector magnitude, dot product, cross product, angle, projection, addition, and distance.计算二维与三维向量的模长、点积、叉积、向量夹角、投影向量、向量加减及空间距离。

Hypothesis Testing & p-Value Calculator假设检验与 p 值计算器 (Z-Test / t-Test)

Perform Z-test and Student’s t-test for sample means, calculate p-values, test statistics, and 95%/99% confidence intervals.支持单样本 Z 检验与 t 检验，精准计算检验统计量、单侧与双侧 p-value 显著性及置信区间。

Normal Distribution & Z-Score Calculator正态分布与 Z-Score 分位数计算器

Calculate Z-score, cumulative probability P(X ≤ x), interval probability P(x1 ≤ X ≤ x2), and percentiles for any mean μ and std dev σ.计算给定均值 μ 与标准差 σ 下的 Z-Score、累积分布概率 P(X ≤ x)、区间概率与标准百分位数。

Confidence Interval Calculator均值与比例置信区间计算器

Calculate 90%, 95%, or 99% confidence intervals for sample means (t / Z distribution) and sample proportions with margin of error.计算 90%、95% 或 99% 置信水平下的样本均值（t 分布 / Z 分布）与样本比例置信区间及抽样误差范围。

One-Way ANOVA Calculator (Analysis of Variance)单因素方差分析计算器 (One-Way ANOVA)

Perform One-Way ANOVA across 3 or 4 sample groups, with F-statistic, p-value, sum of squares (SSB/SSW), and mean squares.多组样本数据的单因素方差分析 (ANOVA)，计算 F 检验统计量、p-value 显著性概率、组间/组内平方和与均方。

Calculus Calculator (Derivative · Integral · Limit)微积分计算器（导数 · 定积分 · 极限）

Numerical derivative at a point, definite integral over an interval, and two-sided limits of any f(x) — powered by the site expression engine.对任意 f(x) 求某点的数值导数、区间定积分与双侧极限——由站内表达式引擎驱动。

Polynomial Regression多项式回归拟合

Fit a polynomial of degree 1–5 to (x, y) data by least squares: coefficients, R², RMSE and the fitted equation.对 (x, y) 数据做 1–5 次多项式最小二乘拟合：给出系数、R²、RMSE 与拟合方程。

Probability Distribution (Binomial · Poisson)概率分布（二项 · 泊松）

P(X = k), P(X ≤ k), mean and variance for binomial and Poisson distributions — computed in log space so huge n never overflows.二项分布与泊松分布的 P(X = k)、P(X ≤ k)、均值与方差——对数空间计算，超大 n 也不会溢出。

Linear Regression (OLS · WLS · GLS)线性回归（OLS · WLS · GLS）

Multiple linear regression with classical or robust standard errors (HC1–HC3, Newey–West HAC, cluster-robust) and AR(1) GLS — coefficients, t tests, R² and F.多元线性回归：经典或稳健标准误（HC1–HC3、Newey–West HAC、聚类稳健），支持 AR(1) 广义最小二乘——系数、t 检验、R² 与 F 检验。

OLS Regression DiagnosticsOLS 回归诊断

Heteroskedasticity (Breusch–Pagan, White), autocorrelation (Durbin–Watson, Breusch–Godfrey, Ljung–Box), normality (Jarque–Bera) and influence (leverage, Cook's distance, DFFITS) on a fitted regression.对回归残差做全面诊断：异方差（Breusch–Pagan、White）、自相关（Durbin–Watson、Breusch–Godfrey、Ljung–Box）、正态性（Jarque–Bera）与强影响点（杠杆值、Cook 距离、DFFITS）。

Quantile Regression分位数回归

Estimate conditional quantiles (median = τ 0.5) by minimising the check loss — robust to outliers and skewness that distort least squares.通过最小化检查损失估计条件分位数（τ = 0.5 即中位数回归）——对扭曲最小二乘的离群值与偏态更稳健。

Mixed Effects Model (Random Intercept)混合效应模型（随机截距）

Linear mixed model by maximum likelihood: fixed effects with random intercepts (and an optional random slope) across groups, plus ICC and variance components.极大似然线性混合模型：固定效应 + 跨组随机截距（可选随机斜率），给出 ICC 与方差分解。

Logistic Regression (Logit · Probit)逻辑回归（Logit · Probit）

Binary outcome regression by iteratively reweighted least squares: coefficients, z tests, likelihood-ratio test, AIC/BIC and average marginal effects.二分类结果的 IRLS 回归：系数、z 检验、似然比检验、AIC/BIC 与平均边际效应。

Count Regression (Poisson · NB · ZIP)计数回归（泊松 · 负二项 · 零膨胀）

Poisson, negative binomial (ML dispersion) and zero-inflated models for count outcomes, with overdispersion diagnostics and AIC comparison.针对计数型因变量的泊松、负二项（极大似然估计离散参数）与零膨胀模型，含过散度诊断与 AIC 比较。

Stationarity Tests (ADF · KPSS)平稳性检验（ADF · KPSS）

Augmented Dickey–Fuller (unit-root null) and KPSS (stationarity null) tests with MacKinnon and Kwiatkowski critical values — they confirm each other from opposite directions.增广 Dickey–Fuller 检验（单位根原假设）与 KPSS 检验（平稳原假设），附 MacKinnon 与 Kwiatkowski 临界值——两个方向互相印证。

ARIMA Forecast (SARIMAX)ARIMA 预测（SARIMAX）

Fit ARIMA/SARIMAX by conditional-sum-of-squares maximum likelihood (parameters constrained to be stable and invertible) and forecast with 95% intervals.以条件平方和极大似然拟合 ARIMA/SARIMAX（参数约束为稳定可逆），并给出带 95% 置信区间的预测。

VAR & Cointegration (Johansen)VAR 与协整（Johansen）

Vector autoregression with stability check, Granger causality F tests and Cholesky impulse responses, plus the Johansen reduced-rank trace statistics for cointegration.向量自回归：稳定性检验、Granger 因果 F 检验、Cholesky 脉冲响应，以及 Johansen 降秩迹统计量协整检验。

State Space & Kalman Filter状态空间与卡尔曼滤波

Local level / local drift / stationary AR(1) unobserved-component models: the Kalman filter and RTS smoother estimate the latent state and forecast with exact likelihood-based variances.局部水平 / 带漂移 / 平稳 AR(1) 不可观测分量模型：卡尔曼滤波与 RTS 平滑器估计潜状态，并以精确似然给出预测及方差。

Developer Tools开发调试工具

JSON, SQL, YAML, XML, HTML, CSS and JS formatters, base64, regex, cron, timestamps, ports, mime and status-code lookups.JSON/SQL/YAML/XML/HTML/CSS/JS 格式化，base64、正则、cron、时间戳、端口、MIME 与状态码查询。

JSON Formatter & ValidatorJSON 格式化与校验工具

Format, validate, minify, escape, and inspect JSON with exact error positions, one-click copy, and file download.格式化、校验、压缩与转义 JSON，精准定位语法错误行号与列号。

SQL Formatter & BeautifierSQL 格式化与美化工具

Format, beautify, indent, and minify SQL queries with keyword auto-capitalization and 100% browser-side privacy.SQL 查询格式化美化与压缩工具，支持关键字自动大写与本地隐私安全。

HTML Formatter & MinifierHTML 格式化与压缩工具

Format messy HTML with proper indentation and self-closing element awareness, or minify HTML to optimize web page delivery.HTML 网页代码规范缩进排版与单行 Minify 压缩工具。

CSS Formatter & MinifierCSS 格式化与压缩工具

Beautify CSS stylesheets with clean rules and property indentation, or minify CSS to a single line for production performance.CSS 样式表格式化排版与单行 Minify 压缩工具。

XML / SVG Formatter & ValidatorXML / SVG 格式化与校验工具

Validate XML syntax, format with customizable 2/4-space indentation, and minify XML/SVG documents in your browser.XML 与 SVG 矢量代码格式化、层级缩进与语法校验工具。

JavaScript & TypeScript Code FormatterJavaScript / TypeScript 代码格式化与压缩

Format and beautify JavaScript & TypeScript code with 2-space indentation and block rules, or minify to a single line.JavaScript 与 TypeScript 代码规范缩进格式化美化、单行 Minify 压缩与括号整理工具。

GraphQL Query & Schema FormatterGraphQL 查询与 Schema 格式化工具

Format GraphQL queries, mutations, subscriptions, and SDL schemas with clean indentation and directive alignment.GraphQL 查询语句 (Query / Mutation) 与 Schema 声明规范格式化、层级缩进与单行压缩。

YAML Formatter & ValidatorYAML 格式化与校验工具

Format and validate YAML with canonical 2-space indentation, or convert between YAML and JSON both ways.规范化缩进格式化并校验 YAML，支持 YAML 与 JSON 双向转换。

TOML Formatter & ValidatorTOML 格式化与校验工具

Format and validate TOML (Cargo.toml / pyproject.toml), or convert between TOML and JSON both ways.规范化格式化并校验 TOML（Cargo.toml / pyproject.toml），支持 TOML 与 JSON 双向转换。

JSON to TypeScript Interface GeneratorJSON 转 TypeScript 接口生成器

Generate TypeScript interfaces from JSON, merging object arrays into one interface with optional keys.从 JSON 生成 TypeScript interface 定义，对象数组自动合并为单一接口并标注可选字段。

XML ⇄ JSON ConverterXML 与 JSON 互转工具

Convert XML to JSON (attributes as @keys, text as #text) and JSON back to XML, fully in your browser.XML 转 JSON（属性映射为 @键、文本为 #text），以及 JSON 转 XML，全程浏览器本地处理。

.env ⇄ JSON Converter.env 与 JSON 互转工具

Convert .env files to JSON and back, with quote handling, export prefixes and inline comments..env 文件与 JSON 互转，完整处理引号、export 前缀与行内注释。

Base64 Encoder / DecoderBase64 编码解码

Encode text to Base64 or decode it back, with Unicode and URL-safe support.文本与 Base64 互相编解码，完整支持 Unicode 中文与 URL 安全模式。

URL Parser & Query FormatterURL 网址与参数格式化

Parse URLs into protocol, hostname, path, and query strings. Decode, sort params, remove tracking tags, and export to JSON.解析 URL 协议、域名、路径与参数，支持参数排序与去除营销追踪参数。

JSON Schema Generator & ValidatorJSON Schema 生成与校验

Infer a draft-07 schema from a JSON document, then validate documents against it — errors listed by JSON path, all in your browser.从 JSON 文档推导 draft-07 Schema，再据此校验其他文档——错误按 JSON 路径列出，全程浏览器本地。

HTTP Status Code LookupHTTP 状态码查询

Look up any HTTP status code — or search by keyword ("redirect", "teapot", "timeout") — with meaning and typical causes in both languages.查询任意 HTTP 状态码——也支持关键词搜索（"redirect"、"teapot"、"timeout"）——中英双语给出含义与常见原因。

MIME Type LookupMIME 类型查询

Map file extensions to MIME types and back: .pdf ↔ application/pdf, .woff2 ↔ font/woff2 — with the practical notes servers actually need.文件扩展名与 MIME 类型互查：.pdf ↔ application/pdf、.woff2 ↔ font/woff2——附服务器实践所需的备注。

Port Lookup (TCP / UDP)网络端口查询

Look up well-known ports by number or service name — SSH, MySQL, Redis, Kubernetes — with security notes on the ones that get you pwned.按端口号或服务名查询常用端口——SSH、MySQL、Redis、Kubernetes——并给高危端口附安全提示。

CSS Grid Visual GeneratorCSS Grid 可视化生成器

Design a grid layout by dragging: edit column and row tracks, drag across cells to place spanning items, and copy the exact CSS — the preview is a real grid, not a mock.拖拽式设计网格布局：编辑行列轨道、拖拽跨格放置元素、一键复制生成的 CSS——预览就是真实网格，不是示意图。

Flexbox Visual GeneratorFlexbox 弹性布局生成器

Tune flex-direction, justify-content, align-items, wrap and gap on a live flex container and copy the CSS — the children react exactly as the properties dictate.在真实弹性容器上调 flex-direction、justify-content、align-items、换行与间距并复制 CSS——子元素的排布就是属性的真实效果。

Number Base Converter进制转换器 (2 / 8 / 10 / 16)

Convert integers between binary, octal, decimal and hexadecimal. Big values are handled with BigInt, so nothing rounds.在二进制、八进制、十进制与十六进制之间互转整数；大数用 BigInt 全程无精度损失。

Unix Timestamp ConverterUnix 时间戳转换器

Convert between Unix seconds / milliseconds and local or UTC wall-clock time — and back: paste a date to get its timestamp.在 Unix 秒、毫秒与本地/UTC 时间之间互转——粘贴日期也能反向得到时间戳。

Cron Expression ParserCron 表达式解析器

Parse Linux 5-field and Quartz 6/7-field cron expressions, expand every field, and list the next execution times.解析标准五段式与秒级六/七段式 Cron 表达式，展开各字段取值并列出下次执行时间。

Regex Tester正则表达式测试器

Test a regular expression against sample text: match count, the matches themselves, and syntax errors.用正则表达式测试样本文本：返回匹配数量、命中的具体内容与语法错误提示。

cURL to Code ConvertercURL 转多语言代码生成器

Convert cURL command lines into JavaScript (fetch/axios), Python (requests), Go, Rust, and PHP code.将 cURL 命令解析并一键转换为 JS (fetch/axios)、Python (requests)、Go、Rust 与 PHP 等多语言 HTTP 请求代码。

UUID / ULID / NanoID GeneratorUUID / ULID / NanoID 生成器

Generate UUID v4, time-ordered UUID v7, sortable ULIDs and short NanoIDs in bulk.批量生成 UUID v4、时间有序的 UUID v7、可排序 ULID 与短 NanoID 标识符。

Random Number Generator随机数生成器

Draw random integers in any range, with or without duplicates.在指定范围内生成随机整数，支持是否允许重复与排序输出。

QR Code Generator二维码生成器

Turn text or URLs into downloadable QR codes, generated entirely in your browser.将文本或网址转换为可下载的二维码，完全在浏览器本地生成。

Unit Converters多功能单位换算

Length, weight, temperature, area, volume, speed, time, data storage, energy, power, and pressure.长度、重量、温度、面积、体积、速度、时间、数据存储、能量热量、功率马力与压力压强换算。

Temperature Converter温度单位换算器

Convert between Celsius (°C), Fahrenheit (°F), Kelvin (K), Rankine (°R) and Réaumur (°Re).支持摄氏度 (°C)、华氏度 (°F)、开尔文 (K)、兰氏度 (°R) 与列氏度 (°Re) 精确换算。

Length & Distance Converter长度与距离单位换算器

Convert between millimeters, centimeters, meters, kilometers, Chinese chi/cun/li, nautical miles, inches, feet, yards and miles.支持毫米、厘米、米、公里、中国市尺/市寸/华里、海里、英寸、英尺、英里换算。

Weight & Mass Converter重量与质量单位换算器

Convert between kg, g, mg, tonnes, Chinese jin (catty), liang (tael), troy ounces, carats, pounds, ounces and stone.支持千克、克、市斤、两、金衡盎司、克拉、磅、盎司等多维度重量单位换算。

Area & Land Measure Converter面积与土地单位换算器

Convert between square meters, hectares, Chinese mu and qing, acres, square feet, square yards and square miles.支持平方米、公顷、中国市亩、顷、英亩、平方英尺、平方英里等多尺度土地面积换算。

Time Duration Converter时间单位换算器

Convert between picoseconds, nanoseconds, milliseconds, seconds, minutes, hours, days, weeks, months and years.支持纳秒、毫秒、秒、分、小时、天、周、月、季度、年及世纪多尺度时间换算。

Data Size & Bandwidth Converter数据存储与带宽换算器

Convert between bits (b, Mb, Gb), bytes (B, KB, MB, GB, TB, PB) and binary kibibytes (KiB, MiB, GiB, TiB).支持比特 (b)、字节 (B)、KB/MB/GB/TB 与二进制 KiB/MiB/GiB/TiB 存储与带宽换算。

Volume & Capacity Converter体积与容量单位换算器

Convert between liters, mL, cubic meters, US gallons, UK gallons, barrels (bbl), cups, tablespoons and cubic feet.支持升、毫升、立方米、美制/英制加仑、原油标准桶、美制量杯与立方英尺容量换算。

Fuel Consumption Converter油耗换算器

Convert between L/100km, km/L, US and imperial mpg — the inverse scales car ads and fuel apps never agree on.百公里油耗 (L/100km)、每升公里数 (km/L) 与美制/英制 mpg 互算，注意油耗换算是倒数关系，数值越大越省油的方向相反。

Speed & Velocity Converter速度单位换算器 (米/秒 · 公里/小时 · mph · 节 · 马赫)

Convert between m/s, km/h, mph, knots, Mach and the speed of light.支持米/秒、公里/小时 (km/h)、英里/小时 (mph)、航速节 (knots) 与马赫 (Mach) 换算。

Energy & Heat Converter能量热量与功换算器

Convert between joules (J), kilojoules (kJ), calories, kilocalories (kcal), watt-hours (Wh), kilowatt-hours (kWh) and BTU.支持焦耳 (J)、千焦、卡路里、大卡 (kcal)、度电 (kWh) 与英热单位 (BTU) 能量热量换算。

Power & Horsepower Converter功率与马力单位换算器

Convert between watts (W), kilowatts (kW), megawatts (MW), metric horsepower (PS), mechanical horsepower (hp) and BTU/h.支持瓦特 (W)、千瓦、兆瓦、米制公制马力 (ps/匹)、英制马力 (hp) 与 BTU/h 功率换算。

Pressure Converter压力与压强单位换算器

Convert between pascals (Pa), kPa, MPa, bar, psi, standard atmospheres (atm), mmHg/Torr, and kgf/cm².支持帕斯卡 (Pa)、千帕、巴 (bar)、磅力/平方英寸 (psi)、标准大气压、托及公斤力换算。

Angle Converter角度单位换算器

Convert between degrees (°), radians (rad), gradians (grad), turns, arcminutes (′) and arcseconds (″).支持度 (°)、弧度 (rad)、百分度 (grad)、转数、角分 (′) 与角秒 (″) 换算，适配三角函数与编程场景。

Finance & Investment金融理财与投资计算

Mortgage prepayment, compound interest, true APR/IRR, inflation, savings goals, and FIRE freedom.房贷提前还款、复利定投、真实年化利率 IRR、通货膨胀、目标储蓄与 FIRE 财务自由。

Mortgage Loan Calculator (Equal P&I vs Equal Principal)房贷计算器 (等额本息 vs 等额本金对比)

Compare level-payment (equal principal & interest) against equal-principal repayment: monthly payment, interest saved, and commercial, provident fund or combined mortgages.等额本息与等额本金同屏对比，支持商业贷款、公积金贷款及组合贷款测算。

Mortgage Prepayment Calculator房贷提前还款计算器

Compare shortening your mortgage term vs reducing monthly payment, and calculate total interest saved.对比缩短还贷年限与减少月供两种提前还贷策略，精准计算节省利息总额。

Rent vs Buy Home Calculator买房 vs 租房收益对比计算器

Compare accumulated net wealth after N years between buying a home vs renting and investing the savings.综合测算 N 年后买房（房贷本息、房屋增值、剩余贷款残值）与租房（首付与每月差额定投理财）的最终净资产沉淀对比。

Loan Payment Calculator贷款月供与还款计划计算器

Monthly payment, total interest and a yearly amortization schedule for any fixed-rate loan.等额本息贷款月供测算、全周期总利息统计与逐年还款摊还明细计划表。

Income Tax & Take-Home Salary Calculator个人所得税计算器 (五险一金/专项扣除/年终奖)

Calculate net income, tax brackets, Five Insurances & Housing Fund, 7 Special Deductions, and Year-End Bonus tax optimization (Separate vs Combined).精准测算个税、五险一金、7项专项附加扣除与年终奖单独计税/合并计税智能优选。

Salary & Hourly Wage Converter薪资与时薪日薪换算器

Convert annual salary into hourly, weekly, biweekly, monthly and daily compensation.年薪、月薪、周薪、日薪与时薪之间快速多维互转换算。

Chinese Uppercase Amount人民币大写金额转换器

Convert a numeric amount into the formal Chinese uppercase form used on invoices and bank slips.把数字金额转换为发票、银行凭证使用的规范人民币大写金额。

True APR & Installment IRR Calculator分期真实年化利率 / 实际利率 IRR 计算器

Convert advertised monthly installment fees or credit card flat rates to real APR and IRR.基于牛顿迭代法求解真实年化利率 IRR 与 APR，揭秘信用卡分期等名义手续费陷阱。

Auto Loan & Out-of-Pocket Calculator汽车贷款与购车落地成本计算器

Monthly car loan payments, interest, down payment, purchase tax, insurance, and total out-of-pocket cost.测算汽车贷款月供利息，综合购置税、车险、上牌费等全套提车落地总成本。

Compound Interest & Investment Return Calculator复利投资与定投收益计算器

Compound growth with configurable compounding frequency, regular monthly contributions, and year-by-year schedule.支持自定义复利计息频率与每月定期定投，按年推演资产长期复利增值轨迹。

Simple Interest Calculator单利计算器

Compute simple interest I = P × r × t with total amount and per-period interest.根据 I = P × r × t 计算单利利息、到期本息总额与逐期明细。

ROI Calculator投资回报率 (ROI) 计算器

Return on investment from cost and revenue, with net profit and return multiple.根据投入成本与回收金额测算投资回报率 (ROI)、净利润与回报倍数。

Savings Goal Calculator目标储蓄规划计算器

Find the required monthly savings to achieve your financial goal by a target date.设定财务储蓄目标金额与到期年限，逆向测算每月所需定投金额与复合收益贡献。

FIRE Calculator (Financial Independence)FIRE 财务自由与提前退休计算器

Determine your target nest egg, projected retirement age, and safe withdrawal strategy using the 4% rule.基于 4% 安全提款法则测算财务自由目标资产、提前退休年龄与提款策略。

Inflation & Purchasing Power Calculator通货膨胀与购买力缩水计算器

Calculate future purchasing power erosion and future equivalent cost based on annual inflation.测算通货膨胀对资金购买力的长期侵蚀影响，展示未来等价物价与贬值幅度。

Discount & Sale Calculator折扣降价与购物优惠计算器

Final price and total savings from a percentage discount, for single or bulk quantities.根据打折折扣百分比计算优惠后价格与节省金额，支持单件或批量核算。

Retirement Drawdown Calculator退休资产提取与耗尽模拟计算器

Simulate how long your nest egg lasts with monthly withdrawals, fixed or growing with inflation.按月提取模拟退休资产的支撑年限，支持固定金额与随通胀逐年上调两种提取策略。

Mortgage Refinance Calculator房贷再融资 (转按揭) 对比计算器

Compare refinancing against your current mortgage: monthly savings, break-even point and lifetime interest.对比再融资方案与现有房贷：月供节省额、手续费回本月数与全周期利息变化。

Rental Yield & Cap Rate Calculator租金收益率与租售比计算器

Gross yield, net operating income (NOI), cap rate, price-to-rent ratio and vacancy sensitivity for a rental property.测算出租房产的毛租金收益率、净营业收入 NOI、资本化率、租售比与空置率敏感性分析。

Credit Card Minimum Payment Calculator信用卡最低还款代价计算器

How long minimum-only payments take to clear a balance, total interest paid, versus a fixed payment plan.揭示只还信用卡最低还款额的清偿时长与利息代价，并与固定月还款方案对比省息。

Annuity Present & Future Value Calculator年金现值与终值计算器

Present and future value of ordinary annuities and annuities due, monthly or yearly — for pension and insurance payout evaluation.普通年金与先付年金的现值/终值测算，支持月付年付，评估养老金与年金保险给付价值。

Net Worth Calculator净资产计算器

List assets and liabilities ("label, amount" per line) and get total assets, total liabilities, net worth and the debt-to-asset ratio.逐行列出资产与负债（"名称, 金额"），得出总资产、总负债、净资产与资产负债率。

Lump Sum vs Dollar-Cost Averaging一次性投资 vs 定投对比

Compare investing everything today against spreading the same total in monthly installments — future values, contributions and the difference, year by year.对比今天一次性全额投入与按月分批定投同一笔总额：终值、投入与差额，逐年展开。

Real Return Calculator (Inflation-Adjusted)真实收益率计算器（扣除通胀）

Strip inflation out of a nominal return: the exact Fisher real rate, plus what an investment actually buys after N years.把通胀从名义收益中剥离：费雪方程精确实际利率，并算出投资 N 年后的真实购买力。

Text Processing文本处理

Case conversion, dedupe and sort, extraction, diffs, CSV ⇄ JSON, markdown tools, word and character counts.大小写转换、去重排序、内容提取、文本对比、CSV ⇄ JSON、Markdown 工具、字数统计。

CSV ⇄ JSON ConverterCSV 与 JSON 互转工具

Convert CSV to JSON (first row as header) or a JSON array of objects to CSV, with full RFC 4180 quoting support.CSV 转 JSON（首行为表头），或将 JSON 对象数组转为 CSV，完整支持 RFC 4180 引号规则。

Case & Naming Converter大小写与命名风格转换器

Convert identifiers or sentences between camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE and more.标识符或句子在 camelCase、PascalCase、snake_case、kebab-case、常量与标题式之间互转。

Line Organizer (Dedupe · Sort · Clean)文本行整理器（去重 · 排序 · 清理）

Clean up pasted lists in one click: remove duplicates, sort alphabetically or by length, trim whitespace and drop empty lines.一键整理粘贴进来的列表：去除重复行、按字母或长度排序、去除行首尾空白与空行。

Text Extractor (URLs · Emails)文本提取器（网址 · 邮箱）

Pull every URL and email address out of pasted text — logs, chat transcripts, pages of prose — one match per line, duplicates optional.从粘贴的任意文本（日志、聊天记录、长文）中提取全部网址和邮箱地址，每行一条，可选择去重。

JSON Diff (Structural)JSON 结构化对比

Compare two JSON documents structurally: added, removed and changed values listed by path — key order and formatting differences are not noise.结构化比较两个 JSON 文档：按路径列出新增、删除与变更的值——键顺序和格式差异不算噪音。

User-Agent ParserUser-Agent 解析器

Paste any User-Agent string and get browser, version, engine, operating system and device class — with crawler and bot detection.粘贴任意 User-Agent 字符串，解析浏览器、版本、引擎、操作系统与设备类型——并识别爬虫与机器人。

HTML Entity Escape / UnescapeHTML 实体转义工具

Escape text to HTML entities (& < ") or unescape named and numeric entities back to characters.把文本转义为 HTML 实体，或将命名实体与数字实体还原为字符。

Word Counter在线字数统计

Live word, character, sentence and paragraph counts plus reading time.实时统计词数、字符数、句子数、段落数与预估阅读时长。

Character Counter字符计数器

Count characters, letters, digits, spaces, symbols and UTF-8 bytes.实时细分统计字符、字母、数字、空格、符号与 UTF-8 字节数。

Markdown Live Editor & PreviewerMarkdown 实时渲染与预览编辑器

Live split-screen Markdown rendering with GitHub Flavored Markdown (GFM), tables, task lists, code syntax, KaTeX-typeset maths, and HTML export.纯本地双栏实时 Markdown 渲染编辑器，支持 GFM 全语法、LaTeX 公式排版与 HTML 导出。

Markdown Table Auto-Align FormatterMarkdown 表格自动对齐与格式化

Format messy Markdown tables into clean, readable, column-aligned ASCII markdown tables with Unicode-aware auto-fitted widths.自动对齐错乱的 Markdown 表格，支持中文全角与英文字符宽度自适应计算，一键格式化完美矩形网格。

Text Diff文本差异对比

Compare two texts line by line and report added, removed and unchanged lines plus similarity.逐行比较两段文本，给出新增、删除、未变行数与整体相似度。

Roman Numeral Converter罗马数字转换器

Convert between Roman numerals and Arabic numbers (1–3999), with strict validation of non-canonical forms.罗马数字与阿拉伯数字互转（1–3999），严格校验非规范写法。

Security & Privacy安全与隐私

Password strength, hashing and HMAC, JWT inspection, subnet math, and what your browser reveals about you.强密码生成、哈希与 HMAC、JWT 检查、子网计算、浏览器隐私指纹自查。

JWT Decoder & FormatterJWT 令牌解码与格式化

Decode JSON Web Tokens (JWT) into Header and Payload, inspect expiration timestamps, and verify claims safely with zero data upload.解析 JWT 令牌 Header 与 Payload，快速检验过期时间与 Claims 字段。

Hash & HMAC Generator (Text & File)哈希与 HMAC 生成器 (文本 / 文件)

MD5, SHA-1/224/256/384/512 and SHA-3 digests of text or dropped files, plus HMAC-SHA256/384/512 — all locally in your browser.文本或拖入文件计算 MD5、SHA-1/224/256/384/512、SHA-3 摘要，并支持 HMAC-SHA256/384/512，全程本地运算。

Browser & Hardware Info浏览器与硬件信息

Read what the browser knows about this machine — CPU cores, memory, GPU, screen, network, codec support — and copy it as a report. Nothing is sent anywhere; the page just prints its own APIs.读取浏览器可知的本机信息——CPU 核数、内存、GPU、屏幕、网络、解码支持——一键生成可复制报告。纯本地读取，不向任何地方发送。

IP Subnet & CIDR Calculator (IPv4 / IPv6)IPv4 / IPv6 子网掩码与 CIDR 计算器

Compute network address, netmask, broadcast, host range from IPv4/CIDR — plus full IPv6 breakdowns with :: expansion and 128-bit prefix math.IPv4/CDIR 网段计算网络地址、子网掩码、广播地址与可用主机范围，并支持 IPv6 网段的 :: 展开、128 位前缀与地址总数计算。

Password Generator强密码生成器

Generate strong random passwords with crypto randomness and ambiguous character filtering.高强度随机密码生成器，采用密码学随机数，支持字符集筛选与易混淆字符排除。

Office & DocumentsOffice 办公与文档处理

Excel workbook analysis and cleaning, the PDF toolkit (merge, split, watermark), and document OCR for PDFs and images.Excel 工作簿分析与清理、PDF 工具箱（合并/拆分/水印）、PDF 与图片的文档 OCR 识别。

Excel Workbook Analyzer & CleanerExcel 工作簿分析与清理器

Drop an .xlsx/.xlsm and see what makes it bloated — unused cell styles, hidden and external defined names, dead links, leftover media, pivot caches — then strip them and download the lean copy. All in the browser.拖入 .xlsx/.xlsm 看清它为何臃肿——未使用的单元格样式、隐藏与外部命名区域、失效链接、残留媒体、透视缓存——勾选清理后下载瘦身副本。全程浏览器本地。

PDF Toolkit (Merge · Split · Rotate · Watermark)PDF 工具箱（合并 · 拆分 · 旋转 · 水印）

Merge, extract or split pages, rotate, watermark, compress (lossless repack), read or strip metadata, PDF → images and images → PDF — all in the browser, nothing uploaded.合并、提取、拆分页面、旋转、加水印、压缩（无损重打包）、查看/清除元数据、PDF 转图片、图片合成 PDF——全程浏览器本地，绝不上传。

Document OCR (PDF · Image → Text)文档 OCR（PDF · 图片转文字）

Extract editable text from scanned PDFs and JPG/PNG/WebP images — Tesseract running as wasm in your browser, English and Simplified Chinese, with a confidence rating per page. Nothing is uploaded.从扫描版 PDF 与 JPG/PNG/WebP 图片提取可编辑文字——Tesseract 以 wasm 在浏览器内运行，支持英语与简体中文，逐页给出置信度。绝不上传。