All Tools - 79 Hand-Picked Free Online Tools

YuanqiZhiKe Toolkit curates 79 hand-picked tools across 37 categories. Each listed tool solves one specific problem, runs entirely in your browser, and keeps your files on your device — nothing is uploaded to a server.

Beyond this curated set, the site also hosts a larger library of additional utilities that remain usable but are not individually curated. Below is the curated list, grouped by category.

AI Business Intelligence

• Excel Formula Generator — Convert plain-English requirements into precise Excel and Google Sheets formulas instantly. Describe tasks like conditional sums, lookups, or deduplic
• KPI Definition Generator — Resolve inconsistent metric definitions by generating three standardized KPI variants (strict, standard, broad) for any business metric. Each definiti
• SQL Query Generator — Translate plain English requests into executable SQL queries instantly. This tool supports multiple database dialects like Postgres and MySQL. Enter y
• Data Insight Writer — Paste metrics and get ready-to-use narratives. This tool converts raw data points into three distinct perspectives: objective facts, story-driven narr
• Report Summarizer — Paste any weekly, monthly, or earnings report and instantly get a structured executive summary with TL;DR, key findings, risks, and recommendations. T

AI Career

• AI Cover Letter Generator — Craft tailored job application letters instantly. Input the job title, company, and your professional background. The tool uses a multi-provider AI en
• Interview Question Generator — Type any role, pick seniority and industry, then generate 10 mock interview questions across behavioral, technical, situational, and culture-fit types

AI Detection

• AI Content Detector — Paste any text and receive a transparent probability score based on five measurable linguistic signals. The detector evaluates AI buzzword density, se
• Plagiarism Similarity Checker — Compare two texts instantly to calculate overlap percentage using local n-gram analysis. Identifies shared phrases and highlights matches within each
• Tone Emotion Analyzer — Detects the emotional undertone of customer emails, social posts, or drafts using a local sentiment lexicon. It visualizes the 3-way sentiment split,

AI Translation

• Business Email Translator — Transform professional correspondence into natural, culturally appropriate multilingual communication. Select a target language and tone, paste your e
• Academic Paper Translator — Translate research papers and abstracts while preserving technical terminology. Select a target language and specific field, then choose to keep origi
• Marketing Copy Translator — Translate and localize marketing copy for multiple target markets simultaneously. This AI-driven tool adapts ads, product descriptions, and email subj
• Paragraph Translator Summary — Triage long documents before committing to a full translation. Paste a contract, report, or article, pick a target language and summary length, then r
• Tone Aware Translator — Transform English text into target languages while preserving distinct registers. This tool generates three variations simultaneously: formal, casual,

AI Writing

• AI Text Rewriter — Rewrite sentences, paragraphs, or articles in Standard, Fluency, or Creative modes. Adjust intensity from subtle to aggressive. Supports multiple AI p
• Readability Score Calculator — Instantly analyze writing clarity using three proven formulas: Flesch Reading Ease, Flesch-Kincaid Grade, and Gunning Fog. The tool counts syllables a

Audio

• File Size Calculator — Estimate uncompressed and compressed audio file sizes instantly. Input duration, sample rate, bit depth, and channels to calculate WAV, FLAC, MP3, AAC
• White Noise Generator — Generate white, pink, and brown noise for sleep, focus, and relaxation. Layer up to three noise types in Mix Mode, add a pure sine oscillator for targ

Automotive

• Car Loan Payoff Calculator — Calculate accelerated car loan payoff with extra monthly payments or one-time lump sums. See how additional contributions reduce total interest and sh
• Car Payment Calculator — Calculate your monthly car payment with this free auto loan estimator. Enter the vehicle price, down payment, trade-in value, loan term, and interest

Beauty

• Hair Color Developer Calculator — Calculate the correct developer volume for your hair coloring project. Enter your starting and target hair levels to get a precise developer recommend
• Nail Polish Mixer — Blend two nail polish colors and see the exact mixed shade with ratio-based calculations. Choose from preset combinations or pick custom colors, then

Cooking

• Pizza Dough Calculator — Calculate exact flour, water, salt, and yeast amounts by weight for any pizza size and style. Uses baker's percentages with preset hydration levels fo
• Sourdough Hydration Calculator — Calculate sourdough hydration levels, starter feeding ratios, and baker's percentages instantly. Enter flour weight, target hydration, salt and levain

Design

• Color Format Converter — Convert colors between HEX, RGB, HSL, RGBA, and HSLA formats instantly. Includes WCAG contrast analysis, luminance calculation, brightness scores, and
• Image Filter Adjust — Adjust image colors and apply filters directly in your browser using the Canvas API. Modify brightness, contrast, saturation, hue, blur, and opacity w
• Image Metadata Viewer — Extract and view EXIF metadata from any image directly in your browser. See camera make and model, lens details, exposure settings, ISO, shutter speed

Education

• Reading Time Calculator — Estimate how long it takes to read any text aloud or silently. Paste your article, speech, or essay, pick a reading or speaking speed in WPM, and inst
• Spelling Bee Solver — Find every valid word from your NYT Spelling Bee puzzle. Enter your 7 hexagram letters and center letter, then click Find Words to instantly reveal al

Finance

• Amortization Schedule Generator — Calculate monthly loan payments and visualize the full payoff timeline. Enter your principal, annual interest rate, and term to get a row-by-row break
• Auto Loan Calculator — Calculate your monthly car payment, total interest, and full loan cost in seconds. Input the vehicle price, down payment, trade-in value, sales tax ra

Fitness

• Body Measurement Tracker — Track your body measurements over time with instant shape analysis. Enter height, weight, chest, waist, and hip measurements to identify your body typ
• Batting Average Calculator — Calculate baseball batting average, on-base percentage, slugging percentage, and OPS from your at-bats, hits, walks, and extra-base hit data. Enter yo

Forms

• Login Form Builder — Design and generate custom login forms with ready-to-use HTML code. Choose between email or username authentication, enable remember-me and password r

Gaming

• Puzzle Generator — Create ready-to-use escape room challenges by selecting from eight distinct puzzle types, including Caesar ciphers, binary codes, and riddles. Configu
• MTG Mana Curve Calculator — Analyze your Magic: The Gathering deck mana curve with this free calculator. Set deck size, average converted mana cost, color count, and ramp cards,

Health

• BAC Calculator — Estimate your blood alcohol concentration using the Widmark formula. Input your gender, body weight, number of standard drinks consumed, and hours ela
• BMI Calculator — Calculate your Body Mass Index with instant health categorization. Enter height, weight, age, and gender to receive your BMI score, ideal weight range

Hobbies

• Crochet Hook Converter — Convert crochet hook sizes between US letters, UK numbers, and metric millimeters instantly. Choose any size from the three linked dropdowns and view
• Model Paint Mixer — Calculate exact paint mixing ratios for scale models and miniature painting. Select base and mix colors, adjust ratios and thinner levels, then get a

Legal

• Court Cost Calculator — Estimate filing fees, service costs, and motion expenses for civil lawsuits. Select your state and case type, enter claim details, and instantly get p
• US Passport Fees Calculator — Estimate total US passport costs instantly. Select your age group, application type, document format, processing speed, and optional extras like photo

Marketing

• Keyword Density Checker — Analyze your content's keyword density and SEO metrics instantly. Paste your text, optionally enter a focus keyword, and get detailed word counts, cha
• SEO Meta Tag Generator — Create full SEO meta tags for titles, descriptions, keywords, canonical URLs, and Open Graph images. See a live SERP preview while typing. Toggle tabs

News

• Polling Margin Calculator — Calculate margin of error for any survey or poll instantly. Enter your sample size, pick a confidence level, and optionally set a finite population. G

Outdoors

• Hiking Time Calculator — Calculate your hiking time using Naismith's Rule. Enter trail distance, elevation gain, and loss to get an accurate estimate. Adjustments for terrain

PDF

• Signature Tool — Add digital signatures to PDFs right in your browser — no uploads required. Create signatures by drawing on a canvas, uploading a PNG or JPG image, or
• PDF to Word Converter — Extract plain text from PDF files and convert to editable .docx documents directly in your browser. Uses PDF.js for client-side text extraction and JS

Pets

• Aquarium Stock Calculator — Plan your fish tank safely with this stocking calculator. Enter your tank volume and choose filtration quality, then add each fish species with its ad

Photography

• Aspect Ratio Calculator — Calculate image dimensions from any aspect ratio, derive ratios from pixel values, or resize while preserving proportions. Choose presets like 16:9, 4
• Photo Print Resizer — Resize your photos for standard print sizes without unwanted cropping. Enter your image dimensions in pixels, pick a print size like 4x6 or 8x10, choo

Productivity

• Discount Calculator — Calculate final prices after one or more sequential discounts, with optional sales tax. Enter the original price, add discount percentages to stack th
• Job Description Generator — Generate professional job descriptions for hiring. Fill in role details, responsibilities, requirements, and benefits, then get a polished Markdown an
• Meeting Cost Calculator — Calculate the true cost of any meeting by entering duration, participant count, and average hourly wage. Apply overhead multipliers for benefits and t

Real Estate

• Real Estate Commission Calculator — Calculate total commission, per-agent earnings, and seller closing costs for any property sale. Input the sale price, commission rate, listing-to-buye
• Mortgage Calculator — Calculate monthly mortgage payment including principal, interest, property tax, and insurance. Enter home price, down payment, interest rate, and loan

Religion

• Bible Verse Lookup — Search Bible passages by book, chapter, and verse reference. Choose from seven public-domain translations including KJV, WEB, and Darby. Fetches live
• Scripture Memory Tracker — Track your Bible verse memorization journey with spaced repetition. Add verses by reference, choose from five translations including KJV, NIV, and ESV

Security

• Password Strength Checker — Test password security in real-time with entropy scores, crack time estimates, and breach checks. Detect common passwords, sequential patterns, and re
• API Key Generator — Generate cryptographically secure API keys directly in your browser. Choose from Random Alphanumeric, Hex, Base64, or UUID-like formats. Adjust key le
• Text Data Masker — Redact personally identifiable information from text before sharing. Detects emails, phone numbers, credit cards, SSNs, IP addresses, and ZIP codes us

Shopping

• Coupon Stack Calculator — Compute final checkout price when multiple coupons stack. Enter the original price, tax rate, and optional cashback. Add percentage or fixed-amount co

Social

• Instagram Character Counter — Count characters in real time for Instagram captions (2200 limit), bios (150 characters), display names (64 characters), and hashtags (up to 30 per po
• Social Media Bio Generator — Generate polished social media bios in seconds. Enter your name, role, location, website, and interests, then pick a tone — professional, casual, funn

Text

• Chinese-English Word Counter — Count words in mixed Chinese-English text with detailed analysis. Separates CJK characters, English words, numbers, and punctuation for accurate word
• Markdown to HTML Converter — Convert Markdown to HTML in real-time right in your browser. Supports headings, bold, italic, lists, code blocks, links, images, tables, and horizonta

Time

• Countdown Generator — Create live countdown timers for any event. Enter the event name, target date and time, choose a timezone, pick from five color themes, and start the

Travel

• Trip Budget Calculator — Estimate your total trip cost by entering destination, duration, travelers, flights, hotel rate, daily expenses, shopping, and an emergency buffer. Th

Utilities

• QR Code Generator — Generate scannable QR codes instantly from any text or URL right in your browser. Adjust size from 64 to 512 pixels, pick from four error correction l
• Election Vote Calculator — Compute election outcomes instantly with support for popular vote, Electoral College, and parliamentary systems. Enter candidate names and vote totals
• Tip Calculator — Split bills and calculate tips with regional presets, itemized charges, and tax support. Choose from preset percentages or enter your own, then get pe
• Date Calculator — Compute the gap between two dates or shift any date by days, weeks, months, and years. Toggle between difference mode and add/subtract mode, enter you

Video

• Video Frame Resizer — Captures individual frames from any video file and scales them to your chosen resolution—4K, 1080p, 720p, or custom dimensions. Pick a preset or enter
• Video to GIF Converter — Turn any video clip into an animated GIF directly in your browser. Set the start time, duration, output width, and frame rate, then convert instantly

Weather

• Apparent Temperature Calculator — Get the real feels-like temperature by combining air temperature, humidity, wind speed, and solar radiation. Supports Fahrenheit or Celsius input, thr
• Beaufort Wind Scale Converter — Instantly map wind speeds to the Beaufort scale. Input velocity in mph, km/h, m/s, or knots to receive force levels 0-12 with descriptive names and ty

Writing

• Email Signature Generator — Generate professional HTML email signatures instantly. Fill in your name, title, company, contact info and social links, then choose from four styles—
• Lorem Ipsum Generator — Generate Lorem Ipsum placeholder text for your design and development projects with complete control. Choose from five unique styles including Classic

All tools are free and run locally in your browser. See how we test them.

Written and maintained by Huang Bin · Last updated October 3, 2026