Free Developer Tools That Run in Your Browser
JSON, JWT, regex, SQL, Base64, cron, hashing, subnets, UUIDs, timestamps and more — every tool processes your input locally, so nothing you paste ever leaves your machine. No installs, no accounts.
JSON, JWT, regex, SQL, Base64, cron, hashing, subnets, UUIDs, timestamps and more — every tool processes your input locally, so nothing you paste ever leaves your machine. No installs, no accounts.
Browser-based screen sharing for instant collaboration and support.
Stack decode, transform, hash and convert steps into one shareable recipe, with magic detection.
Clean, validate, and beautify complex JSON payloads instantly.
Optimize and format SQL queries across multiple database dialects.
Securely inspect and decode JWT headers and payloads on the fly.
Generate high-resolution QR codes or barcodes for links and text.
Convert text or file content safely with standard base64 algorithms.
Transform structured JSON arrays into highly readable data tables.
Compare text blocks side-by-side and highlight syntax differences.
Instantly transform flat CSV spreadsheet files into structured JSON.
Convert configuration files seamlessly between YAML and JSON formats.
Visually build and test server cron job schedules with no guesswork.
Safely encode or decode URL parameters for API requests.
Highlight critical errors, warnings, and trends in server log files.
Test and debug regular expressions with real-time match highlighting.
Convert HTML special characters to secure entities and back again.
IPv4 and IPv6 blocks: hosts, masks, splitting, membership and supernets.
SHA-256, SHA-512, SHA-1 and MD5 of text or files, HMACs, and checksum verification.
Bulk v4, time-ordered v7, namespace v5 and ULIDs, plus a decoder for any id.
Epoch to ISO 8601 and any time zone, with relative time, weeks and date math.
Pretty-print, validate and query XML with XPath, including namespaces.
Every code point, its bytes, hidden zero-width characters and lookalike scripts.
Unbiased random passwords, Diceware passphrases and a strength checker that spots weak patterns.
HEX, RGB, HSL and OKLCH conversion, WCAG and APCA contrast with one-click fixes, palettes.
Binary, hex and decimal at any size, with two's complement, byte order and IEEE-754 floats.
camelCase, snake_case, Title Case and more, plus word count, reading time and line tools.
GitHub-flavored Markdown with a sanitized live preview, table of contents and HTML export.
Check any invoice for UAE FTA e-invoicing compliance and export PINT-AE XML.
Automate your external data pipelines with seamless API flows.
Deploy custom script utilities for logs, reports, and fast fixes.
Launch your optimized static sites connected with GitHub & email.
Custom Enterprise Resource Planning solutions to scale your operations.
High-performance native and cross-platform mobile applications.
Spectacular, high-converting digital portfolios with cinematic aesthetics.
Written explanations of the specification corners and failure modes behind the tools — the reason a bug happened, not just the fix. Browse all guides →
Why length beats symbols, how cracking really works, and Diceware passphrases.
The 4.5:1 rule, why brand colors fail on white, and what APCA changes.
How computers store negative numbers, and the overflow bugs that follow.
Naming conventions for every major language, URLs, SQL and CSS.
GitHub-flavored syntax with the rules behind line breaks and nested lists.
HS256, RS256, ES256 or EdDSA: who can forge, token size, and how to choose.
Why a merge needs the base version and what a conflict really is.
Read any CIDR block in your head and lay out a VPC that can grow.
Why random ids slow large tables and how time-ordered v7 fixes it.
The zero-width space, the BOM, the bidi override, and how to strip them.
Why anyone can read your token's claims, and how alg: none forges one.
Day-of-month and day-of-week are an OR, and */7 is not every seven minutes.
How Norway's country code NO becomes the boolean false.
Catastrophic backtracking, and the three pattern shapes that cause it.
Quoting rules, Excel's locale delimiter, and the formula injection in your export.
The UBL structure, the five-corner model, and the data cleanup to start now.
Most online developer utilities work the same way: you paste your data into a form, it goes to a server you know nothing about, and a result comes back. That is fine for a sample payload and genuinely risky for a production JWT, a query containing customer identifiers, or a log file with session tokens in it.
Layerbit is built the other way round. Every tool here except LayerLink screen sharing is pure client-side JavaScript: the parsing, formatting, validating and converting all happen inside the page already open in your browser. There is no endpoint receiving your input, because there is no endpoint at all.
You do not have to take our word for that, which is the point. Open your browser's developer tools, switch to the Network tab, and use any tool on the site — nothing leaves. Or load a tool, turn off your internet connection, and keep working: it will carry on formatting your JSON quite happily, because nothing it needs is anywhere else.
A formatter that only handles clean input is a demo. The interesting work is in the edge cases, so the tools are built for them: the CSV parser is a proper state machine that handles quoted commas, doubled quotes and newlines inside fields; the JWT decoder verifies HMAC and RSA signatures locally with the Web Crypto API rather than just decoding Base64 and calling it validation; the cron generator shows the next five fire times in UTC, because that is the only reliable way to catch the day-of-month/day-of-week OR rule before it hits production.
Each tool is paired with a written guide covering the specification behind it and the ways it goes wrong in practice. Knowing why an unquoted YAML country code turned into a boolean is what stops it happening twice.
LayerLink is peer-to-peer screen sharing over WebRTC, built for remote support and pair programming without asking anyone to install software or create an account. The video stream travels directly between the two browsers; a signalling service is used only for the initial handshake and never carries video. Sharing a screen requires a desktop browser, since mobile operating systems do not expose screen capture to web pages — but viewing a shared screen works on any modern device.
There is no paid tier, no trial, no account and no upsell. The site is funded by advertising and by the custom engineering work described under Built for You above. We would rather say that plainly than pretend a free toolkit has no business model — and it is worth noting that because the local tools never transmit your input, there is nothing about you for us to collect or sell even if we wanted to.