Hexkit

A fast, offline developer toolbox for macOS, Windows, and Linux — ~40 everyday encoding, formatting, conversion, and inspection tools in one keyboard-driven app. Everything runs locally; nothing you paste ever leaves your machine.

Built with Tauri (Rust core + system WebView) and React 19. All tool logic lives in a pure Rust crate, so the same engine powers the desktop app, a headless CLI, and hexkit:// deep links.

License: PolyForm Noncommercial 1.0.0 — free for personal and other non-commercial use. Commercial use requires a paid license. See License & commercial use.

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Highlights

• 100% offline — all processing happens in local Rust; no network calls.
• Command palette (⌘K) and a filterable sidebar to reach any tool instantly.
• Smart Detection — detects the right tool from your clipboard contents.
• Syntax highlighting on inputs and outputs (CodeMirror 6).
• Pinned & recently-used tools above the sidebar filter.
• Light & dark themes, both designed intentionally.
• Multi-tab workspace — open tools (even the same tool) in separate tabs, with per-tab state that persists across restarts.*
• Headless CLI (hexkit) and deep-link dispatch for future integrations.

* Some advanced capabilities are planned to require a paid license — see below.

Tools

Formatters — JSON format/validate (with JSONPath filter & sort keys), SQL, CSS/SCSS/Less, HTML, XML (with XPath filter), JS minify.

Encoders — Base64 string, URL encode/decode, HTML entities, Hex/ASCII, backslash escape, X.509 certificate decoder, Base64 image, Luhn check, BER-TLV / EMV decoder.

Converters — Unix time, number base (2–36), string case, color (HEX/RGB(A)/HSL(A)/HSB/HWB/CMYK), cron parser, YAML↔JSON, CSV↔JSON, PHP↔JSON, SVG→CSS, HTML→JSX, cURL→code, JSON→code.

Generators — hashes (MD5/SHA-1/256/512 + HMAC), UUID/ULID/Nano ID, random string, Lorem Ipsum, QR code, test credit card numbers (Luhn-valid, Visa / Mastercard / Amex / Discover / JCB / Diners / UnionPay).

Tool-spotlight screenshots: only Text Diff Checker is shown above — dedicated screenshots for the other tools are not yet available.

Text — diff checker (text/JSON/XML), line sort/dedupe, string inspector, RegExp tester (with substitution).

Web — JWT debugger (decode + HS256/384/512 verify), URL parser, HTML preview, Markdown preview.

Getting started

Prerequisites

• Node.js 20+ and pnpm
• Rust (stable)
• Tauri OS prerequisites — see the Tauri setup guide

Run the desktop app

pnpm install
make dev          # or: pnpm tauri dev

Common tasks (see the Makefile)

make web          # frontend only, in a browser
make build        # production frontend bundle
make bundle       # build the distributable desktop app
make cli          # build the headless `hexkit` CLI
make test         # Rust + frontend test suites
make check        # typecheck + lint (clippy) + tests + build

The hexkit CLI

Every tool also runs headless via the hexkit binary, over the exact same dispatcher the desktop app and hexkit:// deep links use. Install it once from inside the app (Hexkit → Install Command Line Tools…) or build it yourself:

cargo install --git https://github.com/trinvh/hexkit hexkit-cli
# → ~/.cargo/bin/hexkit

Calling convention

hexkit <action> '<json-params>'
echo '<json-params>' | hexkit <action>
hexkit 'hexkit://<action>?key=value'

• Actions are namespaced <tool>.<verb> (e.g. json.format, jwt.decode).
• Params are a JSON object; string-shaped results print raw, object/array results print as pretty JSON.
• The deep-link form takes URL-encoded params and is what hexkit://… links from your browser, Raycast, or shell hand off to.

Cheatsheet

# Format JSON (with optional indent + key sort)
hexkit json.format '{"input":"{\"b\":2,\"a\":1}","indent":"  ","sort":true}'

# JSONPath query
hexkit json.query '{"input":"{\"users\":[{\"id\":1},{\"id\":2}]}","path":"$.users[*].id"}'

# Base64
hexkit base64.encode '{"input":"hello"}'
echo aGVsbG8= | hexkit base64.decode

# URL encode / decode (deep-link form, handy in scripts)
hexkit 'hexkit://url.encode?input=hello world'

# Hash digests (single call returns md5/sha1/sha256/sha512)
hexkit hash.generate '{"input":"hello"}'

# HMAC
hexkit hash.hmac '{"algorithm":"sha256","key":"secret","message":"hi"}'

# JWT inspect (header + payload + algorithm + signature)
hexkit jwt.decode '{"input":"eyJhbGciOi…"}'

# UUID v4 (or ulid, nano_id) — `count` and `lowercased` are optional
hexkit uuid.generate '{"kind":"uuid_v4","count":3}'

# Luhn validate + propose a corrected check digit
hexkit luhn.check '{"input":"4111 1111 1111 1112"}'

# Generate Luhn-valid TEST card numbers
hexkit card.generate '{"brand":"visa","count":3}'

# BER-TLV / EMV chip data
hexkit tlv.decode '{"input":"6F2A840E315041592E5359532E4444463031A5..."}'

# Unix time ↔ ISO
hexkit time.convert '{"input":"1700000000","unit":"auto"}'

# Number base conversion (binary / octal / decimal / hex / custom)
hexkit number.all '{"input":"255","base":10}'

# Pretty-print, query and beautify XML / SQL / CSS
hexkit xml.format  '{"input":"<a><b/></a>"}'
hexkit sql.format  '{"input":"select * from users where id=1"}'
hexkit css.beautify '{"input":".a{color:red}","syntax":"css"}'

Discoverability

• Run hexkit --help for usage.
• The full action list is the match in crates/devtools-core/src/actions.rs; every namespace there is a callable namespace from the CLI.
• Anything you can copy as a "Deep link" from the in-app context menu can be pasted as hexkit '…' and produces the same result.

Architecture

crates/devtools-core/   Pure, Tauri-independent tool logic (one module per tool)
crates/hexkit-cli/      Headless `hexkit` binary over the same dispatcher
src-tauri/              Tauri shell (run_action command, clipboard, deep link)
src/                    React UI (tool registry, shared primitives, per-tool views)

Every tool exposes a uniform run(action, params) -> Result<Value, ToolError> function. The desktop app, the CLI, and hexkit:// deep links all route through the same dispatcher, so behavior is identical everywhere.

Tech stack

Tauri 2 · Rust · React 19 · TypeScript · Vite · Tailwind CSS v4 · Zustand · CodeMirror 6 · Vitest.

License & commercial use

Hexkit is source-available, not OSI "open source": it is licensed under the PolyForm Noncommercial License 1.0.0.

• ✅ Free for any non-commercial purpose — personal use, hobby projects, study, research, education, and non-profit/charitable organizations.
• 💼 A paid commercial license is required for any commercial use.
• 🔒 Certain advanced capabilities (a planned Raycast extension and some power-user features such as multi-tab workflows) are intended to require a paid license in the future.

For commercial licensing, please open an issue to get in touch.

Third-party dependencies retain their own licenses (mostly MIT/Apache-2.0).

Contributing

Contributions are welcome — see CONTRIBUTING.md. By contributing you agree your contributions are licensed under the project license.

Acknowledgements

Built on the work of the Tauri, React, CodeMirror, and the broader Rust and TypeScript communities.