Free developer tools.
31 small tools we use while building apps. No signup, and they all run in your browser.
Images and icons
PNG to ICO
Turn a PNG into a multi-size .ico file for favicons and Windows icons.JPG to ICO
Make a multi-size .ico icon from a JPG or JPEG image.SVG to ICO
Render an SVG logo into a crisp multi-size .ico file.ICO to PNG
Pull every size out of an .ico file as separate PNGs.Favicon Generator
Every favicon file a site needs, plus the HTML tags, in one zip.WebP to PNG
Turn a WebP image into a PNG that opens in every app.PNG to WebP
Shrink a PNG into a WebP with a quality slider and live file sizes.SVG to PNG
Render an SVG as a crisp PNG at any size, transparent or on a colour.OG Image Generator
Make a 1200x630 social share image and the meta tags that go with it.
JSON and data
JSON Formatter
Pretty print, sort keys or minify JSON. Big numbers stay exact.JSON Validator
Find the exact line and column of a JSON error, with a plain fix.JSON Diff
Compare two JSON documents and list every change by path.JSON to CSV
Turn a JSON array into a CSV file, with nested objects flattened.CSV to JSON
Parse CSV into a JSON array, with quotes and delimiters handled.YAML to JSON
Convert YAML to JSON, with anchors expanded and errors pointed out.JSON to YAML
Turn JSON into clean YAML, quoted so every parser reads it the same.JSON to TypeScript
Generate TypeScript interfaces or types from a JSON sample.
Encoding and IDs
Text and Markdown
Diff Checker
Compare two texts and see every added, removed and changed line.Case Converter
Turn any text into camelCase, snake_case, kebab-case and seven more cases.Markdown Table Generator
Make a Markdown table from a grid, a spreadsheet paste or a CSV.Markdown to HTML
Convert Markdown to HTML with a live preview, GitHub tables and task lists.
Time and scheduling
Colour
Calculators
Tools for the small jobs. Hype Stack for the big one.
Add a Pro plan at $19 a month with a 14-day free trial.. Let customers invite their team and choose who can do what.. Send a welcome email the moment someone signs up.. Show me which customers are close to their limit this month.. Let people sign in with Google.A free open-source starter with six apps on one API. Auth, billing and emails install as packs, and your coding agent builds the rest.