Format and validate
Clean JSON, markdown, regex, SQL, CSS, HTML, and YAML-like content in the browser.
DevArbor
Developer and text utilities that run offline in your browser — no data sent anywhere.
All tools run entirely in your browser — we don't store your data.What you can do with DevArbor
DevArbor hosts developer utilities for formatting, conversion, validation, encoding, reference, and document workflows. The tools are intended for everyday engineering tasks where a quick local check is faster than opening a full IDE.
Encode and convert
Work with Base64, hashes, colors, timestamps, UUIDs, JWTs, and URL encoding.
Prepare assets and copy
Create signatures, compare text, count tokens, inspect images, and build small artifacts.
Common workflows
Format data, validate regexes, inspect diffs, and decode tokens without pasting into a remote service.
Prepare email signatures, QR-like snippets, colors, and formatted copy for review.
Decode payloads, convert timestamps, generate UUIDs, and compare responses locally.
How we keep the site useful
Developer tools favor local processing and transparent inputs. Sensitive payloads should still be handled carefully, and users should avoid pasting secrets into any website.
All DevArbor tools
Open a tool below to use it immediately. Each page has its own inputs, result area, and help text where needed.
Unit Converter
Convert length, weight, temperature, volume, area, speed, time, data, energy, and pressure with formulas.
Roman Numeral Converter
Convert numbers to Roman numerals and back with step-by-step explanation — includes date converter for tattoos.
Number Base Converter
Convert between binary, octal, decimal, hex, and any base 2–36 with step-by-step explanations and bitwise view.
Text Case Converter
Convert text to UPPER, lower, Title, camelCase, snake_case, kebab-case, and more — live counts and copy buttons.
Word Counter
Live word count, character count, reading time, keyword density, and social platform character limits.
Image Compressor
Compress JPEG, PNG, and WebP images in your browser — no upload, no watermark, batch compression with quality control.
PDF Merger & Splitter
Merge, split, and reorder PDF files entirely in your browser — no upload, no watermark, no file-size limit.
Unix Timestamp Converter
Convert Unix timestamps to human-readable dates — live epoch clock, code snippets in 8 languages, batch converter.
Markdown Editor & Preview
Live GitHub-Flavored Markdown preview with autosave, HTML export, word count, and built-in cheatsheet.
JSON Formatter & Validator
Format, minify, or validate JSON instantly — precise error location and collapsible tree view. 100% client-side.
CSV to JSON Converter
Convert CSV to JSON or JSON to CSV with auto-detected delimiters, type inference, and live table preview.
Online Notepad
Free notepad with autosave, multiple tabs, dark mode, word count, and .txt download — notes stay in your browser.
Diff Checker
Compare two texts side by side with word-level highlighting — your text is never sent to any server.
Aspect Ratio Calculator
Solve for missing dimensions, simplify ratios, and get platform presets for YouTube, Instagram, and TikTok.
Color Picker
Get hex, RGB, HSL, and CMYK codes with shades, complementary palettes, and WCAG contrast checker.
HTTP Status Codes Reference
Plain-English meanings, common causes, and fix guides for every HTTP status code from 1xx to 5xx.
Emoji Copy & Paste
One-tap copy for 600+ emojis — search by name, recently used, skin tone picker, and multi-select mode.
Special Symbols Copy & Paste
Copy any of 800+ Unicode symbols — arrows, stars, hearts, math, currency — with instant search.
Keyboard Shortcuts Reference
Searchable keyboard shortcut cheat sheets for Excel, VS Code, Photoshop, Figma, Word, Gmail, Chrome, and more.
Email Signature Generator
Create a professional HTML email signature in 60 seconds — live preview, 4 templates, one-click copy for Gmail and Outlook.