A curated list of free, browser-based tools that require no signup and run entirely client-side.
All tools on this list are:
- ✅ 100% Free — no premium tier required for core functionality
- ✅ No Signup — use immediately, no account needed
- ✅ Browser-Based — runs entirely in your browser, no data uploaded to servers
- ✅ Privacy-First — your data never leaves your device
| Tool | Description | Source |
|---|---|---|
| GST Calculator | Calculate GST for any amount across 5%, 12%, 18%, 28% slabs. Supports both exclusive and inclusive modes. | wowhow.cloud |
| Income Tax Calculator | Indian income tax calculator with old regime vs new regime comparison. FY 2025-26 slabs. | wowhow.cloud |
| HRA Calculator | Compute HRA exemption under Section 10(13A) for metro and non-metro cities. | wowhow.cloud |
| Home Loan EMI Calculator | Monthly EMI, total interest, and amortization schedule for home loans. | wowhow.cloud |
| SIP Calculator | Systematic Investment Plan returns with compound interest projection. | wowhow.cloud |
| PPF Calculator | Public Provident Fund maturity amount with annual compounding at 7.1%. | wowhow.cloud |
| NPS Calculator | National Pension Scheme corpus and monthly pension estimate at retirement. | wowhow.cloud |
| Gratuity Calculator | Gratuity amount under the Payment of Gratuity Act 1972 for salaried employees. | wowhow.cloud |
| Compound Interest Calculator | Future value with monthly/quarterly/annually/daily compounding frequency. | wowhow.cloud |
| FD Calculator | Fixed deposit maturity amount and interest income for simple and cumulative FDs. | wowhow.cloud |
| Mortgage Calculator | US mortgage calculator with PITI breakdown, amortization table, 15/30yr terms. | wowhow.cloud |
| Tip Calculator | Tip amount calculator with bill splitter for groups and custom tip percentages. | wowhow.cloud |
| GST Invoice Generator | Generate GST-compliant invoices with CGST/SGST/IGST split. Print or save as PDF. | wowhow.cloud |
| Salary Slip Generator | Professional payslip generator with HRA, DA, PF, and deduction breakdown. | wowhow.cloud |
| Tool | Description | Source |
|---|---|---|
| AI Prompt Cost Calculator | Compare API costs across Claude, GPT-4, Gemini with real-time token pricing. | wowhow.cloud |
| JSON Formatter | Validate, format, and minify JSON. Syntax highlighting, error detection. | wowhow.cloud |
| Regex Tester | Test regular expressions with live match highlighting and named groups. | wowhow.cloud |
| Base64 Encoder | Encode and decode Base64 strings. Supports file upload to Base64 conversion. | wowhow.cloud |
| Color Palette Generator | Generate harmonious color palettes from a seed color with export to CSS/Tailwind. | wowhow.cloud |
| Payment Fee Calculator | Calculate Stripe, Razorpay, PayPal processing fees and how much to charge to net a target amount. | wowhow.cloud |
| Cron Expression Generator | Build and validate cron expressions with human-readable descriptions. | wowhow.cloud |
| BMI Calculator | WHO-standard BMI calculator with 6 categories. Height in cm or ft/in, weight in kg or lbs. | wowhow.cloud |
| Tool | Description | Source |
|---|---|---|
| Word Counter | Word count, character count, reading time, keyword density analysis. | wowhow.cloud |
| Meta Tag Generator | Generate SEO meta tags, Open Graph, and Twitter Card HTML. Live preview. | wowhow.cloud |
| Slug Generator | Convert any text to URL-friendly slugs with custom separator and casing options. | wowhow.cloud |
| Readability Score | Flesch-Kincaid, Gunning Fog, SMOG, and Coleman-Liau readability scores. | wowhow.cloud |
| Rent Receipt Generator | Generate printable rent receipts for HRA exemption. All fields editable. | wowhow.cloud |
| Tool | Description | Source |
|---|---|---|
| QR Code Generator | Generate QR codes for URLs, text, WiFi, and contact info. Download as PNG. | wowhow.cloud |
| Password Generator | Cryptographically secure passwords with custom length, character sets, and entropy display. | wowhow.cloud |
| Unit Converter | Convert between 200+ units across length, weight, temperature, area, volume, and more. | wowhow.cloud |
| CAGR Calculator | Compound Annual Growth Rate calculator for investments and business metrics. | wowhow.cloud |
| GSTIN Validator | Validate any Indian GSTIN with checksum verification and state code lookup. | wowhow.cloud |
Contributions welcome! Please read the contribution guidelines first.
To add a tool:
- The tool must be free with no mandatory signup for core functionality
- The tool must run client-side (data stays in browser)
- Add it to the correct category in a table row:
| [Tool Name](URL) | Brief description (1 sentence) | Source | - Submit a pull request
To suggest a tool:
Open an issue with the label tool-suggestion and include the URL and why it qualifies.
To the extent possible under law, the contributors have waived all copyright and related rights to this work.