Everyday developer chores · 9 categories, 87 tools, all offline

KoiX ToolKitOffline developer toolbox

A desktop toolbox built on Tauri 2 and Rust, with 87 tools across 9 categories. Every input is processed on your own device: no account, and no network request beyond the update check you click yourself.

Follow development

Status: Shipping · Updated regularly
For: Developers / ops / designers
Platform: macOS · Windows
Scale: 87 offline tools

Tauri 2 · RustVue 3 and TypeScript for the interface; heavy and security-sensitive work goes to Rust commands.

Strict CSPNo inline scripts, and connect-src allows only Tauri IPC—there is no path out to the network.

Tests on both sidesVitest on the frontend and Rust unit tests, covering a QR generate→scan round trip and RFC test vectors.

The idea

Everyday little tools should not
run on someone else’s server.

Formatting a JSON blob, decoding a JWT, computing a hash—small daily chores that usually get pasted into whatever online tool comes up first. KoiX ToolKit collects them into one local window: open it and work, no account, no connection, and nothing you paste leaves the machine.

Core experience

One window for the whole day’s chores

Pick a category on the left, work on the right

The sidebar lists nine categories, each with its tool count. Star the ones you keep reaching for and they gather under Favorites at the top. Light, dark, and system themes, an interface in Simplified Chinese, Traditional Chinese, and English, and it reopens wherever you left off.

Sensitive data stays local

Passwords, keys, certificates, and images are processed on the device. No telemetry, no accounts—the only outbound request is the update check you click yourself.

Rust where Rust belongs

Hashing, AES-GCM, bcrypt/Argon2, TOTP, barcodes, and image conversion run in Rust; pure logic stays in TypeScript.

Toolkit

9 categories, 87 tools

Everything below already works in the desktop build, computed entirely on your machine with no external service involved.

01Text · 18: String reverse, text diff (with similarity), regex replace, case conversion, word frequency, batch replace, text combining, whitespace compression, dedupe, sort, format, statistics, line-ending conversion, extraction (email/URL/phone/IP), masking, invisible-character detection and cleanup, word wrap, chunking.
02Encoding · 10: URL encode/decode, Base64, Base32, radix conversion, Unicode escapes, HTML entities, Caesar / ROT13 / ROT47, Morse code, text ⇄ hex bytes, Punycode and IDN domains.
03Chinese · 6: Simplified ⇄ Traditional conversion, Chinese numerals and RMB capitalization, pinyin, full-width/half-width conversion, ID-number validation, Chinese name generator.
04Date & time · 4: Timestamp conversion, timezone conversion, cron parsing and building, date calculator.
05Network · 9: IPv4 / IPv6 subnet calculator, CIDR merging and overlap detection, JWT decoding, User-Agent parsing, HTTP status codes, cookie and header parsing, cURL parsing, MIME type and HTTP header lookup.
06Data formats · 10: JSON formatting and validation, YAML ⇄ JSON, TOML ⇄ JSON, INI / Properties conversion, JSON to type definitions (TS / Go / Java), CSV ⇄ JSON / Markdown, SQL formatting, XML processing, JSONPath testing, JSON structure diff.
07Security · 9: CSPRNG password generator, hashes (MD5 / SHA-1 / SHA-256 / SHA-512), AES-256-GCM encryption and HMAC, TOTP / HOTP, bcrypt and Argon2 password hashing, X.509 certificate viewer, password strength checks, RSA keys and encryption, CSR generation.
08Dev tools · 10: Color conversion, regex tester, Lorem placeholder text, Markdown preview, UUID / ULID / NanoID generators, unit converter, .gitignore generator, fake data generator, LICENSE generator, color contrast checker.
09Graphics & image · 11: QR code generation, barcodes (Code 128 / EAN-13), barcode scanning (image or camera), image format conversion (PNG / JPEG / WebP), image ⇄ Base64, EXIF viewing and stripping, favicon generator, SVG optimization and PNG export, palette extraction, crop/resize/rotate, image watermarks.

Boundaries

What it does not do

A toolbox earns its keep by staying restrained. Here is what it explicitly does not promise, stated up front.

It sends no text, passwords, keys, images, or certificates to the network and collects no telemetry; the one request it ever makes is the update check you click.
No sign-up or login; favorites and preferences live only on this machine, and Settings can clear them or reset everything to defaults.
Simplified/Traditional conversion is a common-character mapping and pinyin covers about 180 common characters—neither is a full dictionary.
JWTs are decoded but signatures are not verified, the certificate viewer does not validate trust chains, and SQL formatting and JSONPath cover practical subsets only.

Screens

Everything in one window

Nine categories on the left, the current tool's input and output on the right—from opening the app to finishing the job, you never leave this window.

KoiX ToolKit category overview: nine categories with their tool counts in the sidebar, and a grid of tool cards for the Text category on the right — Category overview · The sidebar carries each category's tool count, and the star on a card moves that tool into Favorites.

KoiX ToolKit tool screen: JSON to type definitions, with JSON input above and the generated TypeScript interfaces below — Tool screen · Input on top, result below, recomputed as you switch between TypeScript, Go, and Java—all on your own machine.

“A tool should wait at your side,
not on someone else’s server.”

KoiX · Product principle 02

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