69 private developer tools

JSON Repair

Fix common JSON-ish mistakes from AI output, logs and copied configs.

JSON Schema Generator

Infer JSON Schema from sample objects and arrays.

JSONPath Query

Query nested JSON with JSONPath-style selectors and copy matched values.

CSV ↔ JSON Converter

Convert CSV to typed JSON and JSON arrays back to CSV, with delimiter detection.

JSON Formatter

Format, validate, and minify JSON in your browser.

JSON to TypeScript

Generate TypeScript interfaces from any JSON sample.

JSON Tree Diff

Compare JSON structurally and report changed paths without whitespace noise.

Encoding

Data URI Encoder

Encode text or SVG assets as data URIs and decode data URIs back to text.

Base64 Encoder / Decoder

Encode text or files to Base64 and decode back, instantly.

URL Encoder / Decoder

Percent-encode URLs and decode them back, with one click.

HTML Entity Encoder

Encode and decode HTML entities — named or numeric.

Date & Time

/time

Unix Timestamp Converter

Convert between Unix timestamps and human-readable dates.

/time

Cron Expression Parser

Translate cron expressions to plain English and next run times.

Crypto & Hash

File Checksum

Compute SHA-1, SHA-256, SHA-384 and SHA-512 hashes for local files.

Secret Scanner

Detect leaked tokens, private keys, JWTs and high-entropy strings before you share text.

UUID Generator

Generate UUID v4 (random) and v7 (time-ordered) identifiers.

Hash Generator

Compute SHA-1, SHA-256, SHA-384 and SHA-512 hashes in browser.

Web

Magic Paste

Paste anything and get routed to the right local tool with confidence signals.

cURL Converter

Turn copied cURL commands into fetch, Python requests and structured request JSON.

Stack Trace Lens

Parse JavaScript, Python and generic stack traces into actionable frames and issue reports.

Workflow Builder

Chain JSON, JWT, Base64, URL, HTML, text and hash operations in one local recipe.

JWT Lab

Sign and verify HS256 JWTs locally, with decoded header and payload.

HTTP Headers Inspector

Parse response headers and score common security headers.

CSP Builder

Build Content-Security-Policy headers with safe defaults.

CSS Specificity Calculator

Rank CSS selectors by specificity and understand which rule wins.

Cookie Parser & Builder

Parse Cookie headers to JSON and build secure Set-Cookie strings.

Meta Tag Generator

Generate title, description, canonical, Open Graph and Twitter meta tags.

CSS Clamp Generator

Generate fluid CSS clamp() values for typography and responsive spacing.

JWT Decoder

Decode and inspect JWT tokens — header, payload, claims.

HAR Viewer

Inspect HAR entries, timings, status codes and slow requests locally.

OpenAPI Mini Inspector

List endpoints, methods and response codes from OpenAPI JSON or common YAML locally.

Text

.env Parser

Convert .env files to JSON or scrubbed .env.example templates.

Markdown Preview

Preview Markdown and copy safe HTML for docs, changelogs and product notes.

SQL Formatter

Format compact SQL queries with keyword casing, line breaks and copy output.

Regex Tester

Test JavaScript regular expressions with live highlighting.

Text Case Converter

Convert text between camelCase, snake_case, kebab-case and more.

Number Base Converter

Convert between binary, octal, decimal, hex and Base64 with BigInt support.

Slug Generator

Convert any phrase into a clean URL-friendly slug.

Text Diff

Compare two texts side-by-side with line- or word-level diffs.

YAML / TOML / INI Converter

Convert common config files between YAML, TOML, INI and JSON locally.

Regex Visualizer

Explain JavaScript regex tokens, matches and named capture groups.

Logfmt / NDJSON Inspector

Parse logfmt and NDJSON logs into structured records for local triage.

Colour

/color

Colour Converter & Contrast

Convert HEX, RGB, HSL, OKLCH and check WCAG contrast ratios.

Generators

Mock Data Generator

Generate deterministic user mock data as JSON or CSV.

QR Studio

Design art QR codes with dots, rounded modules, logos, badges, UTM links and poster exports.

Password Generator

Generate strong random passwords with entropy estimation.

Lorem Ipsum Generator

Generate placeholder text by paragraphs, sentences or words.

Recipe Gallery

Curated local workflow recipes for repeatable developer transformations.

Media

EXIF Inspector & Cleaner

Inspect hidden JPEG metadata, flag GPS privacy risks and export a cleaned local copy.

SVG Studio

Preview, sanitize, minify and convert SVG assets into Data URI or JSX snippets.

Image Optimizer

Compress and resize images locally with Canvas and native browser encoders.

Responsive Image Builder

Generate srcset, sizes and picture markup from an image delivery plan.

Palette Extractor

Extract dominant colors from images as HEX, OKLCH, CSS variables and Tailwind tokens.

LQIP Placeholder Generator

Create tiny blurred image placeholders as Data URLs for perceived performance.

Favicon & App Icon Builder

Generate modern PNG favicon and app icon sizes from one source image.

OG Image Studio

Design and export 1200x630 social sharing images with local Canvas.

Video Inspector

Read local video duration, resolution, MIME type and poster frame with browser APIs.

Video Thumbnail Sheet

Seek through a local video and export a timestamped thumbnail contact sheet.

Subtitle Toolkit

Convert SRT/VTT subtitles, apply timing offsets and detect timestamp issues.

Image Diff

Compare two images on Canvas and highlight changed pixels for UI regression review.

Waveform Poster

Decode audio locally and export a polished waveform cover image.

Audio Loudness Meter

Estimate RMS, peak, crest factor and approximate LUFS from a local audio file.

Media Safety Standard

A product checklist for local processing, memory pressure, cancellation and export limits.

Audio Analyzer

Use your microphone to inspect live waveform, spectrum, RMS, peak, dBFS and rough pitch.

Tone Generator

Generate sine, square, sawtooth and triangle tones in your browser for audio testing.

Mermaid / Diagram Preview

Preview a safe Mermaid-inspired flowchart or sequence diagram subset as SVG.

Reference

/ref

IPv4 Subnet Calculator

Calculate network, broadcast, netmask, wildcard and usable host ranges.

/ref

Unit Converter

Convert length, mass, temperature, data, speed and time units instantly.

/ref

HTTP Status Codes

Searchable reference of HTTP status codes, with colour-coded classes.