Base64 and useful browser tools.
Your tool inputs stay on your device.
Encode or decode Base64 instantly, then use 113 more text, developer, generator, converter and image conversion utilities. No uploads, accounts or conversion APIs.
My Tools
Your private launcher for pinned, recent and frequently used tools.
★ Favorites
Most used
Favorites and usage history use localStorage only. They are never sent to OfflineBase64 or synchronized to an account.
Browse by category
Jump directly to the type of tool you need.
Tool collections
Open a focused workspace for a common task instead of searching the full catalog.
Encoding Toolkit
Base64, Base64URL, URL, HTML, Unicode, binary, hex and classic text encodings in one private collection.
10 tools →JSON Toolkit
Format, compare, extract, escape and convert JSON, JSON Lines, CSV, JWT and query data.
10 tools →Text Cleanup Toolkit
Count, normalize, split, join, sort, extract and transform private text without uploads.
12 tools →Developer Toolkit
Inspect and prepare regex, HTTP, CSS, JavaScript, SQL, XML, Markdown, hashes and identifiers.
12 tools →Converter Toolkit
Reusable time, length, weight, area, volume, pressure, energy, power and coordinate conversion tools.
12 tools →Secure Generators
Generate passwords, API keys, nonces, identifiers, random choices, dates and test values locally.
12 tools →Popular tools
Base64 first, followed by a compact selection of frequently useful utilities.
Base64 Encoder & Decoder
Encode or decode UTF-8 Base64 with optional encrypted history and JSON backup.
JSON Formatter & Validator
Validate, beautify, minify and optionally sort JSON object keys.
YAML Formatter & Validator
Validate, normalize and format common YAML documents locally in your browser.
QR Code Generator & Reader
Generate downloadable QR codes and decode QR images locally when supported.
Color Contrast Checker
Calculate WCAG contrast ratios and preview normal and large text locally.
Secure Password Generator
Create strong random passwords with length and character-set controls.
Cron Expression Parser
Explain five-field cron expressions and calculate upcoming local run times.
Word & Character Counter
Count words, characters, sentences, paragraphs, lines and reading time live.
Your data is not the product
Every conversion runs locally with standard browser APIs. Tool inputs are not transmitted. Optional Google Analytics and Google AdSense load only after user consent, and the downloaded PWA can keep working with no network connection.
Private tools that keep working offline
Offline Tools starts with a complete Unicode-safe Base64 encoder and decoder, then adds focused utilities for text, development data, random values, measurements and Base64 image conversion. Each operation runs with JavaScript and standard browser capabilities on the device you control.
Install the Progressive Web App to keep Base64 and the complete directory available during travel, outages or restricted connections. Every utility also has a dedicated URL, explanatory article, dark and light themes, and controls that adapt to phones and desktop screens.