Free developer tools
Free developer tools that run entirely in your browser. No signup. No upload. No ads. No “PRO unlock”. Dark mode by default because we’re not animals. Built by London developers who got tired of the ad-riddled tool sites that dominate page 1.
The toolbox
Pick what you need
13 tools are live right now. The rest are on the bench with a SOON badge — they ship the same way: browser-only, free, no strings.
Encode & Decode
Base64 Encoder & Decoder
NewEncode or decode text and files. URL-safe variant, live image preview.
/base64URL Encoder & Decoder
NewPercent-encode or decode, plus a parser that breaks a URL into parts.
/url-encodeJWT Decoder
NewDecode the header, payload and claims, check expiry, verify HMAC.
/jwt-decodeHTML Encoder & Decoder
NewEscape or unescape HTML entities — named, decimal or hex.
/html-entitiesFormat & Validate
JSON Formatter & Validator
NewFormat, validate, tree-view and convert JSON. Pinpoint error locations.
/json-formatSQL Formatter
NewPretty-print SQL — dialect-aware, with your choice of keyword case.
/sql-formatXML Formatter
NewBeautify, minify and validate XML. Pinpoint the first error.
/xml-formatYAML ↔ JSON
NewConvert between YAML and JSON in either direction.
/yaml-jsonCSV ↔ JSON
NewTurn CSV into JSON arrays and back again.
/csv-jsonTest & Compare
Regex Tester
NewLive match highlighting, cheat sheet and a common-patterns library.
/regex-testDiff Checker
NewCompare two texts with line and word-level highlights.
/diff-checkHash Generator (MD5/SHA)
NewMD5, SHA-1 and SHA-256/384/512 from text or a file, with checksum compare.
/hash-genUUID Generator
NewGenerate v4, v7 and v1 UUIDs in bulk, copy with one click.
/uuid-genWhy ad-free?
No catch. Here’s the maths.
No ads, because ads ruin tools
Every popular dev-tool site is a minefield of pop-ups, cookie walls and "accept all" dark patterns. We sell SEO consultancy, not your attention, so these pages stay clean. No banners, no interstitials, no newsletter gun to your head.
Nothing leaves your browser
There is no backend. Your JSON, your tokens, your URLs — all of it is processed by JavaScript on your own machine. Open DevTools, watch the Network tab: you will see zero requests carrying your data. We could not log it if we wanted to.
Free because the consultancy pays
These tools cost us almost nothing to run (that is the whole point of browser-only), so there is no PRO tier to upsell. If you ever do need a human — a site migration, a Core Web Vitals mess, a ranking that tanked — the London team is one click away.
From the founder
I build websites for a living, which means I spend half my day pasting JSON into some neon-lit site that wants me to disable my ad-blocker, accept 312 cookies, and sign up to “unlock formatting”. Formatting. A solved problem since roughly 2006.
So we built our own. They run in your browser, they remember nothing, and they will never ask you to upgrade. If they save you ten minutes a week, good. If you ever need a hand with the SEO side of your site, you know where we are.
Need help with your website’s SEO?
The tools are free forever. When you want a human, book a free consultation with our London team.
Book a Free Consultation