All Tools - 79 Hand-Picked Free Online Tools

YuanqiZhiKe Toolkit curates 79 hand-picked tools across 38 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 — Describe any spreadsheet task in plain English and get a ready-to-paste Excel or Google Sheets formula with explanation and a worked example. Covers l
• KPI Definition Generator — Type a metric name and get three definition variants — Strict, Standard, Broad — each with formula, data source, meaning, and watch-outs. Select domai
• SQL Query Generator — Translate plain English into executable SQL across five dialects. Describe totals, averages, top-N rankings, or trends, and get a ready-to-run query w
• Data Insight Writer — Paste raw KPIs and get three insight angles instantly: a dry objective summary, a narrative story, and a recommended next step. The tool auto-detects
• Report Summarizer — Paste any business report—weekly update, earnings note, or project status—and get a structured executive summary with TL;DR, key findings, risks, and

AI Career

• AI Cover Letter Generator — Type the job title, company, and your career highlights, then pick a tone to get a ready-to-send cover letter. The AI drafts a structured four-paragra
• Interview Question Generator — Generate 10 tailored mock interview questions for any role — behavioral, technical, situational, and culture-fit. Questions scale by seniority and ind

AI Detection

• AI Content Detector — Scores text against five signals—AI buzzword density, sentence-length variety, em-dash frequency, vocabulary diversity, transition-word balance—yieldi
• Plagiarism Similarity Checker — Side-by-side text overlap checker that highlights exact shared phrases between two documents. Runs a local n-gram algorithm entirely in your browser—n
• Tone Emotion Analyzer — Drop in any text and get an instant three-way sentiment split, six tone scores (formal, friendly, angry, humorous, worried, joy), and the most emotion

AI Translation

• Business Email Translator — Converts professional emails into natural-sounding translations across six languages. Pick a target language and formal or casual tone, paste your dra
• Academic Translator — Translates research papers while preserving technical terminology. Select target language and academic field, then choose 'Keep original' or 'Bilingua
• Marketing Copy Translator — Translate ad headlines, product pages, and email subjects into six target markets simultaneously. Adapts length limits, idioms, and emojis for each lo
• Translate And Summarize — An AI workflow that processes long text by generating a target-language summary first. This allows users to review key points before committing to a f
• Tone-Aware Translator — Convert English text into formal, casual, or friendly registers in six target languages. Each output includes grammar markers explaining how tone is c

AI Writing

• AI Rewriter — Paraphrase sentences, paragraphs, or articles in three modes — Standard, Fluency, Creative — with a three-level intensity slider. Connect 20+ AI provi

Audio

• File Size Calculator — Estimate audio file sizes for WAV, FLAC, MP3, AAC, and OGG formats. Input duration in minutes, choose your format and quality settings including sampl
• 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 your car loan payoff timeline and interest savings when making extra payments. Enter your loan balance, interest rate, and monthly payment,
• 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

Engineering

• Password Strength Checker — Analyzes password security locally using zxcvbn scoring, entropy calculation, and pattern detection. Tests common passwords, sequential characters, an

Finance

• Amortization Schedule Generator — Calculate a loan amortization schedule with monthly payment breakdowns. Enter the loan amount, annual interest rate, and term to see principal, intere
• 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

• Escape Room Puzzle Generator — Generate escape room puzzles instantly with eight puzzle types including Caesar cipher, substitution, binary, Morse code, riddles, number sequences, r
• 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 precise paint mixing ratios for scale models and miniatures. Select base and mix colors from presets or enter custom hex values, set your ra

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 and test statistical significance between two polling percentages. Enter your sample size, confidence level, and population

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 entirely within your browser — no uploads needed. Create your signature three ways: draw on a canvas, upload a scanned
• To Word Converter — Extract plain text from PDF documents directly in your browser and package it as a downloadable .docx file. No files are uploaded to any server; conve

Pets

• Aquarium Stock Calculator — Calculate safe fish stocking levels for your aquarium. Enter tank volume, choose filtration and stocking approach, then add fish species with size and

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 your meetings by factoring in attendee salaries, overhead multipliers, and opportunity costs. Enter the number of participa

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 your monthly mortgage payment, total interest, and full amortization schedule. Enter home price, down payment, interest rate, and loan term

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

• 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 — Mask emails, phone numbers, credit cards, SSNs, IP addresses, and ZIP codes instantly in any plain text. Choose from asterisk, full, type-label, or ha

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 — Type or paste Instagram captions, bios, display names, or hashtags and get instant character counts against official limits. Track progress with color
• 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 — Calculate tips and split restaurant bills with ease. Enter your bill amount, optionally add tax, pick from regional presets like USA or Japan, or set
• Date Calculator — Calculate the difference between any two dates, or add and subtract days, weeks, months, or years from a base date. Get results broken down into days,

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 — Convert wind speeds between mph, km/h, m/s, and knots into Beaufort scale values. Displays the corresponding force number, descriptive name, and real-

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
• Readability Score — Measure how hard your text is to read using three complementary formulas: Flesch Reading Ease, Flesch-Kincaid Grade, and Gunning Fog. Paste any paragr

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