Privacy-first local developer tools

123 Local Browser Tools for Developers

Format, convert, generate, inspect, and validate developer data in your browser. Most browser-local tools avoid server-side processing, require no account, install as a PWA, and stay open source for verification.

Free
No signup, no account, and no premium tool tier.
Local-first
Browser-local tools keep input and output on your device.
Verifiable
Open source code, trust labels, and security docs are public.

Choose your language

The root page is the x-default entry. It does not force a first-visit redirect, and every localized home remains directly accessible.

Start with common local workflows for JSON, JWT, Base64, hashing, URLs, IDs, regex, and Markdown.

JSON Formatter

Format, validate, and minify JSON payloads instantly.

JWT Decoder

Decode JSON Web Tokens instantly. Never sends your token to any server.

Base64 Encode/Decode

Encode text to Base64 format or decode it back to a readable string.

Hash Generator

Instantly generate MD5, SHA-1, SHA-256, and SHA-512 hashes from text.

URL Encode/Decode

Encode text for safe URL transmission or decode it back to readable string.

UUID Generator

Instantly generate secure, random UUIDs (version 1 or 4) in bulk.

Regex Tester

Test and evaluate regular expressions in real-time natively in your browser.

Markdown Preview

Live split-pane Markdown editor with GFM support.

8 curated categories

Browse tools by task family, runtime privacy, and developer workflow.

Data & Code Formats

20 tools

Format, inspect, and convert JSON, YAML, XML, CSV, schemas, and code-oriented data formats.

Encoding & Crypto

19 tools

Encode, decode, hash, inspect tokens, and work with certificate and key material locally.

Web, API & Network

11 tools

Build, inspect, and debug HTTP, OpenAPI, URLs, user agents, headers, robots rules, and network data.

DevOps & Logs

8 tools

Parse environment files, scrub logs, inspect HAR files, build cron expressions, and prepare operations snippets.

Text & Regex

11 tools

Clean, compare, count, transform, and test text, Unicode, slugs, regular expressions, and markdown content.

Images, SVG & CSS

34 tools

Edit images, extract colors, optimize SVG, generate CSS visuals, and create local design assets.

Generators & Calculators

10 tools

Generate IDs, passwords, timestamps, QR codes, barcodes, random lists, and test data.

Social & Metadata

10 tools

Create open graph metadata, social previews, thumbnails, and share-ready social media assets.

Privacy-first by default

Browser-local tools process input and output on your device. Tools marked External request only contact the network when you explicitly run them, and the project keeps source code, privacy policy, Trust Center, and installable PWA behavior visible for review.