All 138 Free Online Tools — 100% Browser-Based, No Signup
All 138 tools on WOWHOW process data entirely client-side in your browser. No account required. No data transmitted to any server. Zero data retention. Privacy-first by architecture, independently verifiable by inspecting network requests.
Browse 138+ free browser-based developer tools, finance calculators, SEO utilities, and more. Every tool runs entirely in your browser — no signup, no data leaves your device. Built and maintained by the WOWHOW team with 14+ years of hands-on development experience.
Finance & Business (65 tools)
- GST Invoice Generator — GST-compliant PDF invoice in 60 seconds — no signup
- CTC to In-Hand Salary Calculator — Find exact take-home from CTC — FY 2026-27, no signup
- Old vs New Tax Regime Optimizer — Enter deductions — instantly see which regime saves more
- ITR Document Checklist Generator — Get an ITR-ready checklist by taxpayer type and form
- GST Late Fee & Interest Calculator — Estimate filing delay cost for normal and nil returns
- SIP & EMI Calculator — SIP corpus + EMI schedule — visual charts, free, instant
- QR Code Generator — URL, WiFi, UPI & vCard QR codes — PNG/SVG, bulk CSV
- Live Currency Converter — Compare 150+ currencies with live rates
- Privacy Policy Generator (India DPDP) — Generate DPDP-compliant privacy policies for Indian businesses
- Loan Comparison Calculator — Compare up to 4 loan offers side by side
- Gratuity + PF + Leave Calculator — Full F&F settlement — gratuity, PF & leave with tax breakdown
- Rent Receipt Generator — Generate rent receipts for HRA tax exemption
- Stamp Duty Calculator — Calculate stamp duty and registration charges by state
- HRA Exemption Calculator — Exact HRA tax exemption — all 3 formula parts shown
- TDS Calculator India — TDS for salary, rent, fees, FD — PAN vs no-PAN rates
- GST Calculator — Add or remove GST for all 5 slabs — reverse GST too
- Income Tax Calculator FY 2026-27 — See your exact tax in 30 seconds — Old vs New regime
- GSTIN Validator — Validate and decode GSTIN with state and entity details
- ITR Form Selector — Which ITR form should you file? — Step-by-step wizard
- Section 80C Tax Planner — Max Rs 1.5L 80C deduction — ELSS, PPF, LIC, NPS planned
- HSN & SAC Code Finder — Search HSN codes for goods and SAC codes for services
- IFSC Code Finder — Search bank branch IFSC, MICR codes and address
- PPF, NPS & FD Calculator — Government savings scheme calculator with maturity tables
- Salary Slip Generator — Generate payslips with Indian statutory deductions
- 8th Pay Commission Calculator — Calculate revised salary under 8th CPC fitment scenarios
- Advance Tax Calculator — Plan quarterly advance tax with 44ADA support
- Section 44ADA Tax Calculator — Presumptive tax for professionals — compare 44ADA vs regular
- Full & Final Settlement Calculator — Calculate complete F&F settlement in one place
- Capital Gains Tax Calculator — LTCG & STCG — Budget 2024 rates, indexed vs flat for property
- PPF Calculator — 15-year PPF maturity at 7.1% — year-wise table, free
- Gratuity Calculator — Gratuity for Govt & private sector — correct formula, instant
- FD Calculator — Calculate fixed deposit maturity value with TDS
- Lumpsum Calculator — Calculate lumpsum investment returns with growth table
- Compound Interest Calculator — Calculate compound interest with growth chart and contributions
- NPS Calculator — Estimate NPS retirement corpus and monthly pension
- Retirement Calculator — Plan your retirement with inflation-adjusted corpus and pension estimates
- Home Loan EMI Calculator — Exact EMI + total interest + amortization — any Indian bank
- SWP Calculator — Plan systematic withdrawals from mutual fund investments
- CAGR Calculator — Calculate compound annual growth rate of any investment
- Mortgage Calculator — Monthly payment with PMI, amortization & total cost
- Investment Returns Calculator — Calculate investment growth with inflation adjustment
- Paycheck Calculator — Estimate your take-home pay after federal and state taxes
- Debt Payoff Calculator — Plan your debt-free journey with snowball or avalanche strategies
- 401k Calculator — Estimate your retirement savings with employer match and compound growth
- Net Worth Calculator — Calculate your total net worth and compare to US averages by age
- Auto Loan Calculator — Calculate your monthly car payment instantly
- Tax Bracket Calculator — See exactly how your income is taxed by bracket
- US Capital Gains Tax Calculator — Federal capital gains tax — long-term 0%/15%/20% and short-term rates
- US Auto Loan Calculator — Monthly payment, true cost & amortization for US auto loans
- US Tax Bracket Calculator 2026 — 2026 IRS federal tax brackets — effective rate, marginal rate, take-home
- CPF Calculator — Singapore — Calculate CPF contributions with OA/SA/MA breakdown by age
- DPDPA Compliance Checklist Generator — Get audit-ready for India's data protection law before May 2027
- India Capital Gains Tax Calculator — LTCG & STCG tax on equity, property, gold, and mutual funds — Budget 2024 rates
- Roth IRA Contribution & Growth Calculator — Project tax-free retirement wealth with 2026 IRS limits
- HELOC Calculator — Home equity line of credit limit, draw & repayment payments
- US Student Loan Repayment Calculator — Compare all federal repayment plans — Standard, IBR, PAYE, SAVE
- Mortgage Refinance Break-Even Calculator — See exactly when refinancing pays off
- Rent vs Buy Calculator 2026 — Find your break-even year — true cost of renting vs buying over 5–30 years
- Invoice Generator — Create & download professional invoices instantly
- Loan Amortization Calculator — Full payment schedule with principal & interest breakdown
- Inflation Impact Calculator 2026 — See how inflation erodes your salary and expenses in real time
- Bitcoin Halving ROI Calculator — Historical Bitcoin cycle returns — no API, no signup
- EPF Calculator — Project your PF maturity corpus with EPS diversion
- 50/30/20 Budget Planner — Split income into needs, wants and savings instantly
- FIRE Calculator — Find your FIRE number and the age you can retire early
Developer (40 tools)
- JSON Formatter & Validator — Format, validate & diff JSON — runs entirely in browser
- Regex Playground — Test regex live — railroad diagrams + plain English explained
- Color System Generator — One color in, full design system out
- Cron Expression Builder — Build cron jobs visually — no syntax to memorize
- .env File Validator & Converter — Validate, compare, and convert .env files
- Diff Checker — Compare two texts and spot every difference instantly
- SQL Formatter — Beautify and format SQL queries instantly
- CSS Gradient Generator — Create beautiful gradients with a visual editor
- CSS Box Shadow Generator — Design beautiful CSS shadows with a visual editor
- Text Case Converter — Convert text between 12 case formats instantly
- Color Contrast Checker — WCAG AA/AAA accessibility compliance in real time
- CSS Layout Generator — Build Flexbox & Grid layouts visually with Tailwind export
- Favicon Generator — Create favicons from text, emoji or image — all sizes
- Hash Generator — MD5, SHA-1, SHA-256, SHA-512 hashes in your browser
- JWT Decoder — Decode JWT header, payload & expiry — tokens stay private
- XML Formatter & Validator — Format, validate and minify XML with syntax highlighting
- CSS Clip-Path Generator — Create complex clip-path shapes with visual drag handles
- Glassmorphism Generator — Generate frosted glass CSS effects with live preview
- CSS Animation Generator — Build custom keyframe animations with visual easing editor
- CSS Unit Converter — Convert px, rem, em, vh, vw with Tailwind equivalents
- Markdown Editor — Write Markdown with instant live preview and HTML export
- cURL to Code Converter — Convert cURL commands to Python, JavaScript, Go, and PHP
- Coding Assistant ROI Calculator — Estimate payback for Claude Code, Cursor, and Copilot seats
- AI Prompt Cost Calculator — Compare AI API costs across every major LLM
- AI Model Cost Comparison Calculator — Compare real costs across 10 AI models — Claude, GPT, Gemini, DeepSeek, Grok
- Payment Gateway Fee Calculator — Compare real costs of Stripe, Dodo, Paddle & LemonSqueezy
- Base64 Encoder / Decoder — Encode/decode text & files — URL-safe, MIME, data URLs
- AI Token Counter — Count tokens & estimate costs for GPT-5.4, Claude 4.6 & Gemini 3.1 Pro
- Codebase Dependency Visualizer — Visualize project dependencies as an interactive graph
- Color Picker — Pick colors & convert between HEX, RGB, HSL, CMYK
- Binary Converter — Convert between binary, decimal, hex & octal instantly
- AI Token & Cost Estimator — Paste text → token count + cost breakdown across 7 major AI models
- Image to PDF Converter — Drag-drop images, reorder, and download as a single PDF — all in browser
- YAML to JSON Converter — Convert YAML ↔ JSON bidirectionally with live validation
- JSON to CSV Converter — Paste a JSON array → get CSV with auto-detected headers
- URL Encoder / Decoder — Encode, decode, and parse URL components instantly
- Subnet Calculator — Enter IP/CIDR, get network address, broadcast, host range, and masks
- HTTP Status Code Reference — Search all HTTP status codes 1xx-5xx with descriptions and examples
- Docker Run to Compose — Convert docker run commands to docker-compose.yml instantly
- README Generator — Generate a formatted README.md with badges, TOC, and live preview
SEO & Content (8 tools)
- Meta Tags & OG Preview — Preview how your site looks on Google, Twitter & more
- Image Compressor — Compress, resize, watermark & convert images in bulk
- Word & Character Counter — Count words, characters, and reading time
- Schema Markup Generator — Generate JSON-LD structured data for Google rich results
- YouTube Earnings Calculator — Estimate your YouTube revenue by views and niche
- Instagram Engagement Rate Calculator — Check your engagement rate with industry benchmarks
- Medium Formatter — Write Markdown, paste perfectly into Medium — with readability scoring, SEO analysis, and 20+ writing tools
- Readability Checker — Score text with Flesch-Kincaid, grade level, and sentence highlights
Utilities (25 tools)
- Base64 Encoder / Decoder — Encode and decode Base64 instantly
- UUID Generator — Generate unique IDs with one click
- Unix Timestamp Converter — Convert timestamps to human dates and back
- Password Generator — Crypto-strong passwords — entropy shown, never stored
- Age Calculator — Calculate exact age with government exam eligibility
- CGPA to Percentage Converter — Convert CGPA to percentage for any Indian university
- WhatsApp Link Generator — Create click-to-chat links with QR codes
- Percentage Calculator — Four percentage modes in one compact view
- Typing Speed Test — Test WPM, accuracy and exam eligibility in 1 minute
- Number to Words Converter — Convert numbers to words in Indian format (lakhs/crores)
- PAN Card Validator — Validate PAN format and decode all 10 characters
- Tip Calculator — Calculate tip, total, and split the bill
- BMI Calculator — Body Mass Index and healthy weight range
- TDEE & Calorie Calculator — Find your daily calorie needs for any goal
- Time Zone Converter — Convert time across 500+ world time zones instantly
- Random Number Generator — Generate truly random numbers, picks, and shuffles
- Password Strength Checker — Test password strength and get instant security feedback
- Unit Converter — Convert length, weight, temperature, and 5 more unit types
- Pomodoro Timer — Focus timer with 25-min sessions & break intervals
- GTA 6 Countdown Timer — Live countdown to the most anticipated game ever
- Steam Deck Price Comparison Calculator — Compare models, build your kit, see real value vs consoles
- Color Palette from Image — Extract dominant colors from any image as HEX, RGB, and HSL
- HEIC to JPG Converter — Convert iPhone HEIC photos to JPG in your browser — no upload needed
- ATS Resume Checker — Score your resume against any job description — keyword gap analysis in seconds
- Rent Agreement Generator India — Generate an 11-month residential rent agreement with standard clauses — free