About OnlineToolingKit.com

Free, privacy-friendly web tools. No signup required. Most processing happens in your browser.

Hi, I'm Tom Winters from the Netherlands. I built this site as a tooling website—mostly for myself, but I want to share it with others too.

I'm testing the limits of AI-assisted building with this project: what's possible without a full server and SQL. I don't want to save your data—I want to help you check, transform, and generate data. Keeping it safe for everybody.

Contact

Questions, feedback, or suggestions? Use the form below or email me at info@onlinetoolingkit.com.

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Tools

Network

• Speed Test – Measures download, upload, ping and jitter. Test data is sent to our server for measurement.
• HTTP Headers Checker – Fetch a URL and see response headers and status code. Server-side proxy.
• SSL Certificate Checker – Check SSL/TLS certificate validity and expiry for any domain.
• DNS Lookup – Look up A, AAAA, MX, TXT, NS, CNAME, SOA records.
• IP Info – See your public IP. Optional geolocation via ip-api.com.
• Subnet Calculator – CIDR, network address, broadcast, usable hosts. All client-side.
• WiFi dBm Explainer – Understand WiFi signal strength in dBm. Compare values and visualize coverage. All client-side.
• Port Reference – Look up common TCP/UDP ports (22, 80, 443, 3306…). All client-side.

Images & Design

• Image Resize – Resize and convert PNG, JPG, WebP. Runs in your browser. No uploads.
• Image Compress – Reduce image file size with quality slider. JPEG, WebP, PNG. All client-side.
• Favicon Generator – Generate favicon pack from one image. All client-side.
• Palette from Image – Extract color palettes from photos. Export CSS, Tailwind, JSON. All client-side.
• Font Library – Browse Google Fonts, preview with your text, copy embed code. Fonts load from Google.
• Gradient Generator – Create linear, radial, and conic CSS gradients. All client-side.
• Box Shadow Generator – CSS box-shadow with sliders, live preview, copy. All client-side.
• Border Radius Generator – CSS border-radius with preview, copy. All client-side.
• Color Picker – HEX/RGB/HSL, harmony palettes, color blindness preview, WCAG contrast. All client-side.
• Random Color – Generate random HEX/RGB/HSL colors. All client-side.

Business

• Job Cost Calculator – Materials, labor, machines, write-offs → total cost and suggested price. All client-side.
• Margin vs Markup – Convert between margin and markup, set prices from cost. All client-side.
• Break-Even Calculator – Fixed costs, variable cost, price → break-even units. All client-side.
• ROI Calculator – Investment vs return → ROI %. All client-side.
• Billable Hour Rate – Target income + overhead → hourly rate. All client-side.
• CAC / LTV Calculator – Customer acquisition cost and lifetime value. All client-side.

Calculators

• Standard Calculator – Basic arithmetic. All client-side.
• Geometry Calculator – Area, perimeter, volume. All client-side.
• Age Calculator – Birth date to exact age. All client-side.
• Day of Week – Which weekday was a date? All client-side.
• Week Number – ISO week number for any date. All client-side.
• Planet Distance Calculator – Distance between planets. All client-side.
• Date Difference – Days between two dates. All client-side.
• Percentage Calculator – X% of Y, add/subtract %. All client-side.
• Unit Price Calculator – Compare prices per unit. All client-side.
• Tip Calculator – Bill + tip %, split between people. All client-side.
• Compound Interest Calculator – Principal, rate, years → future value. All client-side.
• Loan / EMI Calculator – Monthly payment from principal, rate, term. All client-side.
• Countdown Timer – Pick date/time, see live countdown. All client-side.

Converters

• Currency Converter – Uses Frankfurter.app for exchange rates. No API key. Rates cached for 1 hour.
• Crypto Converter – Uses CoinGecko for crypto prices. No API key. Rates cached for 5 minutes.
• JSON Formatter – Format, validate and minify JSON. All client-side.
• Base64 – Encode and decode Base64. All client-side.
• URL Encode – Encode and decode URL parameters. All client-side.
• Hash Generator – MD5, SHA-1, SHA-256 hashes. All client-side.
• Timestamp – Convert Unix timestamps to dates and vice versa. All client-side.
• Length Converter – m, km, miles, feet, inches, cm, mm, yards. All client-side.
• Temperature Converter – °C, °F, Kelvin. All client-side.
• Timezone Converter – Convert time between timezones. Uses Intl API. All client-side.
• Angle Converter – Degrees, radians, gradians. All client-side.
• Pressure Converter – bar, psi, kPa, atm. All client-side.
• Speed Converter – km/h, mph, m/s, knots, ft/s. All client-side.
• Volume Converter – liters, gallons, cups, m³, ft³. All client-side.
• Data Size Converter – bytes, KB, MB, GB, KiB, MiB. All client-side.
• Number Base Converter – Decimal, binary, hex, octal. All client-side.
• Roman Numerals – Convert numbers to Roman numerals and back. All client-side.
• CSV ↔ JSON – Convert between CSV and JSON. All client-side.
• PDF Tools – Merge, split PDFs and convert PDF to images. All client-side.

Text & Writing

• Lorem Ipsum – Generate placeholder text. All client-side.
• Case Converter – Convert text case (upper, lower, title, camelCase). All client-side.
• Character Counter – Count characters, words and lines. All client-side.
• Markdown Preview – Live Markdown to HTML preview. All client-side.
• Diff Checker – Compare two texts line by line. All client-side.
• List Tools – Sort, randomize, remove duplicates, reverse lists. All client-side.
• Morse Code – Encode and decode Morse code. All client-side.

Generators

• Password Generator – Generate secure random passwords. All client-side.
• Password Strength – Check password strength in real time. All client-side.
• Hashtags Generator – Generate hashtags for Instagram, TikTok, Twitter. All client-side.
• Random String – Generate random alphanumeric strings. All client-side.
• Random Number – Random integers in a range. All client-side.
• Slug Generator – Convert text to URL-friendly slugs. All client-side.
• Fake Data – Generate fake names, emails, addresses for testing. All client-side.
• UUID Generator – Generate UUID v4 identifiers. All client-side.
• QR Code – Generate QR codes from text or URLs. All client-side.
• Barcode – Code 128 barcode generator. All client-side.

Developer

• Meta Tags Generator – Open Graph and Twitter Card meta tags for social sharing. All client-side.
• MCP JSON Generator – Build MCP config for Cursor, Claude. All client-side.
• .env Formatter – Format and validate .env files. All client-side.
• API Schema Validator – Validate OpenAI/Anthropic tool schemas. All client-side.
• SQL Formatter – Format and minify SQL. All client-side.
• XML Formatter – Format and validate XML. All client-side.
• Cron Generator – Build cron expressions visually. All client-side.
• API Mock Generator – Generate fake REST/JSON from schema. All client-side.
• Regex Tester – Test regular expressions against sample text. All client-side.
• JWT Decoder – Decode and inspect JWT tokens. All client-side.
• HTML Entities – Encode and decode HTML entities. All client-side.
• URL Parser – Parse URL into components. All client-side.
• User Agent Parser – Parse browser, OS, device from UA string. All client-side.
• Cron Explainer – Explain cron expressions in plain English. All client-side.
• Semver Compare – Compare semantic version numbers. All client-side.
• CSS Formatter – Format or minify CSS. All client-side.
• HTML Formatter – Pretty-print HTML. All client-side.
• YAML ↔ JSON – Convert between YAML and JSON. All client-side.
• Escape/Unescape – Escape strings for JSON, HTML, URL, regex. All client-side.
• Unicode Lookup – Character to code point and vice versa. All client-side.
• Font Awesome Guide – CDN, npm, and usage examples for Font Awesome icons. All client-side.
• CSS Cursors – All CSS cursor values with live preview. Click to copy. All client-side.

Your Device – See detailed info about your browser, screen, and capabilities. All client-side.

Privacy Statement – What data we collect and how we use it.