Why these tools are different
The internet is full of free online tools, and most share an awkward common trait: they send your data to a server you don't control, demand a signup, push six intrusive banner ads, and quietly disappear when their business model collapses. SAW TOOLS was designed on opposite principles. Three deliberate choices define this site and guide every technical decision we make.
1. Everything runs in your browser
None of our tools transmits anything to a server. When you generate a password, the cryptographic randomness comes from your browser's crypto.getRandomValues() function. When you encode Base64, the work happens in your tab's JavaScript engine. When you convert a color, the calculation uses only native CSS and JS functions. This client-side approach has three direct consequences: your data never leaves your device, the tools keep working offline once the page is loaded, and we have no technical means to log what you do. You can verify this at any time by opening your browser's network inspector — you will see no outgoing requests to saw-tools.me while you use a tool.
2. No accounts, no limits, no lock-in
No signup, no password to create, no email to provide, no "free trial" that morphs into a subscription, no quota that empties after five uses. SAW TOOLS is free and will stay free. The site is funded by discreet Google AdSense advertising, plus a few contextual affiliate links clearly labelled inside our long-form guides where they actually help (for instance our password manager comparison). You owe us nothing, you give us nothing, and you keep full control of your experience. If you run an ad blocker, the site will work exactly the same — we have no opposition to that choice.
3. Transparent and editorialised
Every tool comes with an explainer page that describes what it does, its limits, and when not to use it. You'll also find a blog with nine long-form guides that dig into the technical concepts behind each tool: why Base64 is not security, how randomness in computing actually works, what makes a password truly strong, which color model to pick in modern CSS. This editorial transparency is deliberate: we believe an informed user makes better choices than a captive one. None of these articles are AI-generated and dumped raw; every guide is reviewed and edited before publication.
Each tool in detail
Every tool was built to solve a specific problem, without bloat and without data collection. Here is what each one does, with a pointer to the related deep-dive guide if you want to learn more.
Password Generator
Generates cryptographically random passwords from 6 to 64 characters, with a length slider and toggles for lowercase, uppercase, digits, symbols, and exclusion of ambiguous characters. Randomness comes from crypto.getRandomValues(), not Math.random(). To understand why that distinction is critical, read our guide on password anatomy. And if you want to take the next step and adopt a vault, check our 2026 password manager comparison. Direct access: password generator.
Password Leak Checker
Checks whether a password appears in the Have I Been Pwned database of over 900 million leaked passwords — without ever revealing it. Your browser hashes the password with SHA-1 and sends only the first five characters of that hash (the k-anonymity model), so the password never leaves your device. It's the natural companion to the generator: find out if a password is compromised, then replace it with a strong unique one. To understand how leaks happen and why password reuse is the real danger, read our field guide to data breaches. Direct access: password leak checker.
Unit Converter
Converts between SI and imperial units for length, weight, temperature, volume, area, speed, time, and computer data (the famous GB vs GiB trap). The tool uses the exact conversion factors defined by the BIPM. To understand the fascinating history of measurement units, their pitfalls (the 1999 Mars Climate Orbiter loss), and the 2019 kilogram redefinition based on the Planck constant, read our complete guide to unit conversion. Direct access: unit converter.
QR Code Generator
Encodes any text or URL into a downloadable QR code in PNG or SVG. Generation is entirely local — your content is never sent to our servers, which matters when you encode a Wi-Fi password, personal contact details, or an internal business URL. The code follows the ISO/IEC 18004 standard, is readable by all standard scanners, and remains usable long-term (a static QR has no external dependency). For deep coverage of error correction levels, professional use cases, and security concerns (the "quishing" wave of 2024-2026), see our complete guide to QR codes. Direct access: QR code generator.
Secure Random Number Generator
Generates unbiased random integers in any range, with or without duplicates, using a CSPRNG (cryptographically secure generator) combined with rejection sampling to guarantee uniform distribution. Many free tools use Math.random() and modulo, which introduce bias and make outputs predictable — unsuitable for security usage. To understand the difference between PRNG, CSPRNG, and quantum randomness, and which one fits which scenario, read our guide to randomness in computing. Direct access: random number generator.
Base64 Encoder / Decoder
Encodes text (UTF-8 and emojis included) into standard Base64 or Base64url. The tool detects the direction (encode or decode) based on the active tab. It's the reference tool for embedding images via data URIs, debugging JWTs, handling PEM certificates, or transmitting binary inside JSON. Important: Base64 is NOT encryption — to grasp what that implies and all the common developer pitfalls, read our complete guide to Base64. Direct access: Base64 encoder / decoder.
Color Converter
Instantly converts between HEX, RGB, HSL, and HSV with a live color picker, without sending a single value to a server. Useful for quickly grabbing the HEX code of a perceived color, checking that a design meets WCAG contrast, or exploring variations of a hue. In 2026, the emerging oklch() format changes everything for modern CSS designs (clean interpolation, P3 support); to understand all color models and accessibility considerations, read our guide to web colors. Direct access: color converter.
Markdown to HTML
Real-time Markdown preview with copyable HTML output on the right. The tool supports both CommonMark and GitHub Flavored Markdown (tables, task lists, autolinks). Useful for drafting a README, formatting a structured message, or experimenting with syntax. To understand the many Markdown dialects, the ecosystem (Obsidian, Notion, MDX), and why Markdown has become the preferred format of LLMs in 2026, see our complete Markdown guide. Direct access: Markdown to HTML converter.
Scientific Calculator
Calculator with two modes (simple and scientific) — trigonometry (sin, cos, tan and inverses, in degrees or radians), logarithms (ln, log, log₂), exponentials, factorial, π, e, and nested parentheses. The engine respects PEMDAS/BIDMAS order of operations and uses IEEE 754 double precision (15-17 significant digits). To understand how these mathematical functions work, their classic pitfalls (angle mode, floating-point precision, negative modulo), and their history, read our guide to scientific computing. Direct access: scientific calculator.
