Free Online Developer Tools — 24+ Tools, No Signup
Developer tools that respect the data you paste into them. Many online JSON formatters, JWT decoders, and regex testers send your input to a server for "processing" — which is almost always actually surveillance. The data developers paste is often production payloads, internal API responses, or partial credentials, and exposing it to a third party is a real security risk.
Every developer tool on Toolkiya runs in your browser. The JSON formatter, regex tester, diff checker, hash generator, base64 encoder, color converter, JWT decoder, URL encoder, hex/binary converter, and timestamp converter all execute locally. Nothing is sent anywhere. You can verify this in DevTools.
The tools are also designed for quick use without ceremony. No signup, no auto-formatting that breaks deliberate spacing, no promo banners that obscure the result. The output area is wide and selectable, the buttons are obvious, and keyboard shortcuts work where you'd expect them.
All Developer Tools
Image to Base64
Image to Base64 converter free — encode to data URL instantly
JSON Formatter
JSON formatter online free — validate, beautify & minify JSON
Base64 Converter
Base64 encoder decoder online free — encode text & files
Lorem Ipsum
Lorem ipsum generator — placeholder text for designs & mockups
URL Encoder
URL encoder decoder free online — encode, decode & analyze URLs
DOCX to Markdown
DOCX to Markdown converter free — Word to MD in 1 click
Markdown to HTML
Markdown to HTML converter — with live preview, free online
HTML to Markdown
HTML to Markdown converter free — clean MD output instantly
JSON to CSV
JSON to CSV converter free online — export arrays in 1 click
CSV to JSON
CSV to JSON converter free — import spreadsheet as JSON
Regex Tester
Regex tester live — test regular expressions with highlights
Diff Checker
Diff checker online — compare two texts & highlight differences
Hash Generator
Hash generator MD5 SHA256 online free — SHA-1, SHA-512 too
Color Converter
Color converter — HEX to RGB, HSL, HSV, CMYK free online
Timestamp Converter
Timestamp converter unix — epoch to date, free online tool
JSON ↔ YAML Converter
Convert JSON to YAML and YAML to JSON online free — instant format conversion
Cron Expression Generator
Cron expression generator free — build & explain cron schedules visually
CSS Gradient Generator
CSS gradient generator free — create linear, radial & conic gradients visually
Meta Tag Generator
Meta tag generator free — create SEO meta tags, Open Graph & Twitter cards
Favicon Generator
Favicon generator free — create favicons from text, emoji or image for any site
System Design Tool
System design tool online free — draw HLD, LLD, infrastructure diagrams with cost estimation
Password Generator
Password generator free — strong random passwords with symbols, numbers & letters
Number Base Converter
Binary hex octal decimal converter free — convert number bases instantly
JWT Decoder
JWT decoder online — inspect token header, payload & signature
Frequently Asked Questions
Can I paste production data into these tools?
Yes. All processing happens in your browser. Paste a JWT, a JSON payload, or a regex pattern — none of it is sent to a server. Verify in DevTools by opening the Network tab and watching for outgoing requests.
Do these tools work offline?
Yes. Each tool is a self-contained page that loads its logic on first visit and runs locally thereafter. Useful for working from a flight or behind a corporate firewall that blocks unfamiliar domains.
How does the regex tester compare to regex101?
The Toolkiya regex tester is more focused — JavaScript flavour only, with live match highlighting and explanation. regex101 is more thorough (multiple flavours, debugger, library) but routes everything through their server. For quick pattern testing, Toolkiya is faster; for deep debugging across regex flavours, regex101 has more depth.
What hash algorithms do you support?
MD5, SHA-1, SHA-256, SHA-384, SHA-512, and CRC32. SHA-256 and SHA-512 use the browser's native Web Crypto API; the rest are JavaScript implementations.
Does the JWT decoder verify signatures?
It can verify HMAC signatures (HS256, HS384, HS512) when you provide the secret. RSA and ECDSA verification requires the public key — supported but the key must be in PEM format. For untrusted JWTs, use signature verification before trusting the payload.
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