Private by Design.
Instant by Default.
Built for developers, founders, creators, and finance professionals: code generation, asset studio, AST transforms, and financial calculators — all running 100% locally in your browser without external data uploads.
Calculators
Client-side financial estimation and statutory fee calculators with mathematical transparency.
Stripe Fee Calculator 2026 — Card Processing & Reverse Invoicing
Calculate exact Stripe processing fees, net payouts, and reverse invoicing amounts (how much to charge to receive $X net) with zero server data transfer.
VAT Calculator 2026 — Add or Extract VAT & Sales Tax
Calculate exact Value Added Tax (VAT) and sales tax additions or reverse deductions instantly. Free, private, client-side VAT calculator with country presets (UK, Germany, France, Turkey, etc.).
PayPal Fee Calculator 2026 — Merchant Fees & Reverse Invoicing
Calculate exact PayPal commercial transaction fees, net payouts, and reverse invoice amounts (how much to charge to receive $X net) with zero server data transfer.
Freelance Hourly & Day Rate Calculator 2026 — Billable Rate Modeling
Calculate your true freelance hourly and day rates based on desired net income, business overhead, non-billable administrative time, and tax reserves. 100% private.
Profit Margin & Markup Calculator 2026 — Gross Margin vs Markup
Calculate gross profit margin, markup percentage, revenue price, and profit multiplier instantly. Master the mathematical difference between margin and markup with zero server tracking.
Mortgage Calculator 2026 — Amortization Schedule & Early Payoff
Calculate your monthly mortgage payments, total interest costs, and full amortization schedule. Simulate extra principal payments and dual annual/monthly interest rates.
Compound Interest Calculator 2026 — Investment Growth & Compounding Schedule
Calculate compound interest on investments, savings, and retirement funds. Simulate monthly contributions, compounding frequencies, and inflation-adjusted real purchasing power.
Converters
Type-safe transformations, AST schema extraction, and binary encodings executed in browser workers.
JSON to TypeScript Converter — Strict Interface Generator
Convert JSON objects and API payloads into strict, type-safe TypeScript interfaces and types entirely client-side using Web Workers.
JSON to Schema & Code Types Studio (Java POJO, Go, Pydantic, C#, Rust)
Convert JSON payloads to strongly-typed models across Java (POJO, Lombok, Record), Go struct, Python Pydantic v2, C# Record, and Rust Serde client-side.
Base64 Encode & Decode — UTF-8 & URL-Safe Online Converter
Encode text or files into Base64 and decode Base64 strings back to UTF-8 plain text with zero server upload. Supports URL-Safe RFC 4648 Base64.
CSV to JSON & SQL Converter — RFC 4180 Client-Side Parser
Convert CSV tables to typed JSON arrays or SQL INSERT statements entirely client-side. Supports commas, semicolons, tabs, custom table names, and automatic delimiter detection.
JWT Decoder & Inspector — Zero-Upload Online JWT Token Viewer
Decode, inspect, and verify JSON Web Tokens (JWT) client-side with zero server upload. Instant expiration countdown, claims analyzer, and HMAC/RSA signature verification.
YAML to JSON & Reverse Converter — Bidirectional & Multi-Doc Parser
Convert YAML to JSON and JSON to YAML instantly in your browser. Supports multi-document streams (---), Kubernetes manifests, Docker Compose, custom indentation, and zero server uploads.
cURL to Code Converter — Instant Multi-Language HTTP Client Generator
Convert cURL commands to JavaScript Fetch, Axios, Python Requests, Go, Rust, and Java. 100% client-side parser with zero server upload for private tokens and APIs.
Online JSON to Java POJO Converter — Jackson & Lombok Support
Convert JSON to clean Java POJO classes with Jackson @JsonProperty annotations and Lombok @Data getters/setters. 100% client-side AST generation with zero server uploads.
Online JSON to Go Struct Converter — Idiomatic Golang Struct Tags
Convert JSON payloads to idiomatic Go (Golang) struct definitions with json:"key,omitempty" tags and proper initialisms (ID, URL, HTTP, API). 100% client-side AST generation.
Online JSON to Pydantic v2 Converter — Python BaseModel Models
Convert JSON payloads to Python Pydantic v2 BaseModel classes with Field(alias="..."), type annotations, and Optional support. 100% client-side AST generation with zero server uploads.
Generators
Fast, browser-based generators for passwords, UUIDs, passphrases, and cron schedule expressions.
Cryptographic Password Generator — Secure & Client-Side
Generate cryptographically secure passwords and Diceware passphrases locally in your browser using the Web Crypto API (CSPRNG). Zero server storage.
UUID Generator — Online Bulk RFC 4122 v4 & RFC 9562 v7 GUIDs
Generate cryptographically secure UUID/GUID v4 and time-ordered UUID v7 tokens entirely in your browser using Web Crypto CSPRNG. Bulk generate up to 100.
Cron Expression Generator & Schedule Calculator — Visual Builder
Online visual cron schedule builder, parser, and human-readable translator. Generates upcoming run times and validates standard 5-part cron expressions client-side.
JWT Generator & Signer — Zero-Upload Online Mock Token Builder
Generate, sign, and build custom JSON Web Tokens (JWT) client-side with zero server upload. Instant Unix expiration calculator, ephemeral RSA keypair generator, and OAuth2/Bearer mock presets.
Cron Every 5 Minutes Generator (*/5 * * * *) — Syntax & Schedule Tester
Generate, test, and validate the crontab expression for running tasks every 5 minutes (*/5 * * * *). Interactive visual builder with human-readable description and next execution timestamps.
Cron Every Hour Generator (0 * * * *) — Syntax & Schedule Tester
Generate, test, and validate the crontab expression for running tasks every hour (0 * * * *). Interactive visual builder with human-readable description and next execution timestamps.
Cron Daily at Midnight Generator (0 0 * * *) — Syntax & Schedule Tester
Generate, test, and validate the crontab expression for running tasks daily at midnight (0 0 * * *). Interactive visual builder with human-readable description and next execution timestamps.
Formatters
Query beautifiers, syntax validators, and structured code formatters with zero server compute.
JSON Formatter & Validator — Pretty Print, Minify & Inspect
Format, validate, beautify, and minify JSON online with instant syntax error detection, line/column markers, and alphabetical key sorting. 100% private and client-side.
SQL Formatter & Beautifier — Multi-Dialect Online Query Formatter
Format, beautify, and indent SQL queries online. Supports PostgreSQL, MySQL, SQLite, MariaDB, BigQuery, and T-SQL with configurable keyword casing and zero server upload.
Media & Graphics
Zero-upload image croppers, Apple squircle rounders, code snapshot visualizers, and multi-platform app icon generators.
Code to Image Studio — Beautiful Code Snippet Visualizer
Generate beautiful, high-resolution code images for Twitter, LinkedIn, and blog posts with custom themes, macOS frames, and instant clipboard copy.
App Icon Generator & Favicon Studio (iOS, Android, PWA)
Generate production-ready app icons and favicons for iOS, Android, Web, and PWA in all standard resolutions with zero server uploads.
Privacy-First Image Cropper, Resizer & Squircle Studio
Zero-upload image cropper and corner rounder. Apply Apple squircles, custom border radiuses, aspect ratios (1:1, 16:9), and matte backdrops directly in your browser with 100% client-side privacy.
Text Tools
In-browser text diff comparison, duplicate line removal, case conversion, regex testing, and markdown export.
Markdown to PDF Converter — Zero-Upload Styled Document Studio
Convert Markdown into beautifully styled, print-ready PDF documents client-side. Zero server uploads, custom themes, and full privacy for confidential notes and specs.
Duplicate Line Remover 2026 — Delete Duplicate Lines & Sort Online
Remove duplicate lines from text, CSVs, and lists instantly in your browser. Case-sensitive matching, whitespace trimming, and sorting with 100% on-device privacy.
Text & Code Diff Checker — Side-by-Side & Unified Diff Tool
Compare two texts or code snippets client-side. Side-by-side and unified views, character-level difference highlighting, whitespace toggles, and zero server upload.
Online Regex Tester & Explainer — Real-Time Regular Expression Evaluator
Test, evaluate, and debug regular expressions in real-time. Highlights match groups, named captures, substitutions, and explains syntax with zero server upload.
Case Converter & Slug Generator — camelCase, snake_case, PascalCase, and URL Slugs
Transform text and identifiers into camelCase, PascalCase, snake_case, CONSTANT_CASE, kebab-case, Title Case, and URL-friendly slugs with international diacritic transliteration. 100% private in-browser Web Worker.