Free Online Tools That Run in Your Browser

gavel

Google Safe Browsing Checker

Check whether Google Safe Browsing currently lists a URL for malware, phishing or unwanted software, and what to do if your own site is flagged.

psychology

AI GDPR Risk Mapper

Answer three questions about an AI system and get the GDPR obligations it triggers: lawful basis, special category data, DPIA and Article 22 decisions.

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Meta Tag Analyzer

Check a page's meta tags for the problems that actually affect indexing and click-through.

code

JSON Formatter

Format and beautify JSON in your browser. Pinpoints syntax errors by line and column, flags unsafe integers, and never uploads your data to a server.

router

MAC Address Lookup

Look up the manufacturer behind a MAC address from its OUI prefix, and identify locally administered and randomised addresses.

security

Hash Generator

Generate MD5, SHA-1, SHA-256 and SHA-512 hashes in your browser. Compare checksums and verify file integrity with nothing uploaded to a server.

security

Password Generator

Generate strong random passwords and passphrases in your browser using the Web Crypto API. Nothing is transmitted, logged or stored.

code

Regex Tester

Test regular expressions against sample text with live match highlighting, capture groups and flag control. Runs entirely in your browser.

business_center

Invoice Generator

Build a professional invoice in your browser and download it, with the fields that determine whether you actually get paid.

code

JWT Generator

Create a signed HS256 JWT from a JSON payload and a secret, using the Web Crypto API in your browser. Nothing is sent anywhere.

router

Port Scanner

Check which common ports respond on a host and understand what each exposed service means. Scan only systems you are authorised to test.

business_center

SaaS Risk Heatmap

Pick the SaaS apps your company runs, add your own, and get a heatmap ranking each by data criticality times access scope, with the risk each carries.

security

MTA-STS Policy Generator

Generate the mta-sts.txt policy file and the _mta-sts DNS TXT record that tell sending mail servers to require TLS for your domain. Testing and enforce modes.

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Robots.txt Generator

Generate a valid robots.txt with crawler-specific rules, sitemap references and AI crawler directives, with each rule explained.

school

APA Citation Generator

Build APA 7th edition references and in-text citations, with the rules that changed from the 6th edition.

business_center

Currency Converter

Convert between currencies and understand why the rate you get differs from the mid-market rate you looked up.

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Schema Markup Generator

Generate valid JSON-LD structured data for Article, FAQPage and Organization types, ready to paste into a page head. Runs in your browser.

business_center

Follow-up Email Generator

Generate a concise follow-up email template for meetings, invoices, or outreach.

attach_money

Debt Avalanche Calculator

Model the debt avalanche method, which clears the highest interest rate first and costs the least overall.

router

Network Latency Estimator

Estimate round-trip time between two points from distance, transmission medium and router hops, and see what that RTT costs in TCP and TLS handshakes.

build

Download Speed Estimator

Estimate how long a download takes at a given connection speed, allowing for real-world overhead.

attach_money

Risk Reward Ratio Calculator

Calculate risk-reward ratio and the win rate it requires to be profitable.

security

Password Strength Checker

Measure password strength by entropy and pattern analysis rather than character-class rules. Checked entirely in your browser.

code

ESLint + Prettier Config Builder

Generate an eslint.config.js flat config with Prettier for JavaScript or TypeScript, Node or browser, plus .prettierrc and a legacy .eslintrc.json.