SimonOS Utility Launchpad

Useful tools, ready at boot.

A calm browser toolbox with a retro SimonOS shell. Convert, clean, measure, and process everyday files without accounts, popups, or maze-like dashboards.

57

Live utilities

6

Active families

6

Tracked signals

Time & Date

Timestamps, timezones, scheduling, and date debugging.

Converters

Fast unit conversions and everyday format helpers.

Text & Code

Case conversion, slugs, labels, and code-friendly text.

Image

Local resize and export flows for everyday image cleanup.

PDF Tools

Private file workflows for merging and preparing documents.

Document Tools

Printable exports and text extraction for practical document work.

Live Now

The tools that are already booted.

57 featured tools

Timestamp Converter

Convert Unix timestamps, ISO strings, and readable dates without guessing which format you are looking at.

Timezone Converter

Translate one meeting time across cities and named time zones with quick previews for the places you care about.

Length Converter

Switch between metric and imperial length units instantly, with quick swaps and practical equivalents.

Base64 Converter

Encode and decode UTF-8 text as Base64 for payloads, tokens, and debugging.

URL Encoder / Decoder

Encode and decode percent-escaped URL text for query strings, route parameters, links, and copied payload fragments.

Text Case Converter

Flip text between sentence case, title case, uppercase, lowercase, slugs, and developer-friendly identifiers.

Format, validate, minify, and sort JSON payloads for APIs, configs, and logs.

Decode JSON Web Token headers and payloads locally so you can inspect claims without verifying or uploading the token.

Generate SHA-1, SHA-256, SHA-384, and SHA-512 hashes from local text with hex and Base64 output.

Test JavaScript regular expressions against local text and inspect matches, indexes, capture groups, and flags.

Color Converter

Convert HEX, RGB, and HSL color values with a live swatch, copyable CSS output, and contrast guidance.

Count words, characters, sentences, paragraphs, lines, unique words, and estimated reading time.

Lorem Ipsum Generator

Generate predictable placeholder paragraphs with adjustable sentence and word counts.

Password Generator

Create strong local passwords with configurable length, character sets, and entropy estimates.

Number Base Converter

Convert integers between binary, octal, decimal, hexadecimal, and other bases up to base 36.

Break absolute or relative URLs into protocol, host, path, query parameters, and fragments.

HTML Entity Converter

Encode HTML-sensitive characters or decode common named and numeric HTML entities locally.

CSV to JSON Converter

Convert CSV text into formatted JSON rows with quoted-field support and custom delimiters.

Date Difference Calculator

Calculate days, hours, and calendar parts between two YYYY-MM-DD dates with optional inclusive counting.

Sort pasted lines alphabetically or numerically, remove duplicates, and copy the cleaned list.

Text Diff Checker

Compare two blocks of text with a local line diff and copy a unified-style change summary.

Generate one or many random UUID v4 identifiers for fixtures and records.

Resize PNG, JPEG, and WebP images locally in the browser with aspect-ratio locking and quick export formats.

Image Compressor

Compress PNG, JPEG, and WebP images locally with quality-controlled browser exports.

Crop images by exact pixel coordinates and dimensions, then export a local browser copy.

JPG to PNG Converter

Convert JPG and JPEG images into PNG files locally in the browser.

PNG to JPG Converter

Convert PNG images into JPG files with quality and background color controls.

Rotate PNG, JPEG, and WebP images by 90, 180, or 270 degrees locally.

Flip images horizontally, vertically, or both ways without uploading the file.

Watermark Adder for Images

Add text watermarks to images with position, opacity, size, and color controls.

Image Sharpener

Apply an adjustable local sharpening filter to PNG, JPEG, and WebP images.

Blur PNG, JPEG, and WebP images with an adjustable browser-side filter.

Image Color Inverter

Invert image colors locally to create a negative-style PNG, JPEG, or WebP export.

Combine multiple PDF files locally in the browser with explicit ordering.

Optimize a PDF locally by rebuilding page data and reporting the actual byte savings.

Split a PDF locally by every page, fixed page counts, or custom ranges with separate PDF downloads.

PDF Page Extractor

Extract selected pages from a PDF into a new local file using simple page numbers or ranges.

PDF Page Deleter

Delete unwanted pages from a PDF locally and download a cleaned copy with the remaining pages preserved.

Rotate every page or selected PDF page ranges by 90, 180, or 270 degrees in the browser.

JPG to PDF Converter

Combine JPG and JPEG images into one local PDF with image-sized, A4, or Letter pages.

PNG to PDF Converter

Combine PNG images into a single local PDF with image-sized, A4, or Letter pages.

Image Batch to PDF

Combine JPG, JPEG, and PNG image batches into one local PDF with one image per page.

Add Watermark to PDF

Add a centered text watermark to every page of a PDF with local opacity, color, and rotation controls.

PDF Editor (Text Add)

Add short positioned text stamps to selected PDF pages without uploading the source file.

Crop selected PDF pages by top, right, bottom, and left margins using local browser processing.

PDF Page Reorder

Reorder PDF pages locally by entering a new page sequence, including descending ranges.

PDF Page Number Adder

Add customizable page numbers to every page of a PDF with local format, position, and color controls.

CSV to PDF Converter

Turn pasted CSV rows into a clean printable PDF table with local parsing and page-size controls.

PDF Signature Adder

Add visible typed signature text to selected PDF pages for approvals and review copies.

PDF Form Filler

Inspect fillable PDF form fields, edit their values as JSON, and export a filled local copy.

PDF Annotation Adder

Draw visible review notes or labels onto selected PDF pages without uploading the source file.

PDF Header/Footer Adder

Add centered header and footer text to every page of a PDF with local font and color controls.

PDF Page Size Changer

Place PDF pages onto A4, Letter, Legal, or custom page sizes with fit, fill, and stretch modes.

PDF Bates Numbering

Add sequential Bates identifiers to every PDF page with custom prefix, padding, and placement.

PDF Metadata Editor

Edit PDF title, author, subject, and keyword metadata locally without changing visible page content.

Markdown to PDF

Turn markdown notes into a local, printable PDF with headings, lists, quotes, and code blocks.

Extract selectable text from PNG, JPEG, and WebP scans or screenshots in the browser.

Next Up

Build queue for the 500-tool system.

Client-side first No signup flow Tools over dashboards Retro shell, calm workflow

Queue clear

The first document-tool wave is live.

Pick the next utility family when it is time to expand beyond converters, image tools, PDFs, and document extraction.

Feedback Loop

Help choose the next utility.

Request a tool, report a broken edge case, or point out a workflow that should feel faster. The best suggestions become the next small browser tools.

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