guides
Use Cases
60 step-by-step guides for common developer tasks — each using a free, browser-based tool.
JWT Decoder
4 guidesHow to decode a JWT in your browser
Instantly inspect the header and payload of any JWT without installing software.
How to inspect an Auth0 JWT token
Read the claims inside an Auth0 access token or ID token to debug permissions and user data.
How to check if a JWT has expired
Read the 'exp' claim from a JWT to determine when the token expires or whether it's already expired.
How to verify a JWT HS256 signature
Confirm that a JWT signed with HMAC-SHA-256 has not been tampered with by verifying it against a known secret.
JSON Formatter
4 guidesHow to pretty-print a JSON API response
Convert a minified or compact JSON API response into human-readable, indented output for inspection.
How to minify JSON for production
Remove all whitespace from a JSON file to reduce its size before embedding it in code, APIs, or config files.
How to sort JSON keys alphabetically
Reorder all keys in a JSON object alphabetically at every level of nesting for consistent diffs and readability.
How to validate JSON syntax and find errors
Check whether a JSON string is syntactically valid and locate the exact position of any parse errors.
Image Converter
4 guidesHow to convert PNG to WebP online
Reduce PNG file size by converting to WebP format for faster web page loading.
How to convert JPEG to AVIF online
Shrink photo file sizes dramatically by converting JPEG images to the AVIF format.
How to convert WebP to PNG online
Convert a WebP image to PNG for compatibility with tools and platforms that don't support WebP.
How to convert SVG to PNG online
Rasterize an SVG vector file to a PNG bitmap for use in contexts that require raster images.
Background Remover
3 guidesHow to remove the background from a product photo
Create a transparent-background PNG of a product for e-commerce listings, catalogs, and marketing assets.
How to remove the background from a headshot photo
Create a transparent or white-background version of a professional headshot for LinkedIn, CVs, and company pages.
How to extract a logo from a screenshot
Isolate a company logo by removing the surrounding background from a screenshot or image.
LCOV Coverage Viewer
6 guidesHow to view a Jest LCOV coverage report online
Inspect Jest test coverage results from a lcov.info file without installing a local HTML viewer.
How to view an Istanbul/nyc coverage report online
Parse an LCOV .info file from Istanbul or nyc to visualize JavaScript coverage without serving HTML files.
How to view Python coverage.py reports as LCOV
Convert a Python coverage.py report to LCOV format and view it online.
How to analyze a Vitest coverage report with LCOV
View Vitest test coverage from a lcov.info file to identify under-tested TypeScript files.
How to view a coverage report from GitHub Actions
Download and inspect the LCOV coverage artifact from a GitHub Actions workflow run.
How to read and understand an LCOV .info file
Understand the LCOV .info file format to debug coverage data or write a custom parser.
Image Resizer & Cropper
5 guidesHow to resize an image to exact pixel dimensions
Scale an image to a specific width and height for social media, email, or web use.
How to crop an image online for free
Remove unwanted areas from an image by cropping to a specific region or preset aspect ratio.
How to resize an image for social media
Scale images to the correct pixel dimensions for Instagram, LinkedIn, Twitter/X, Facebook, or YouTube.
How to rotate an image 90 or 180 degrees online
Fix incorrect image orientation by rotating a photo 90, 180, or 270 degrees.
How to reduce image file size by resizing
Reduce a large image's file size by scaling down dimensions before converting to a modern format.
Base64 Encoder / Decoder
2 guidesHash Generator
4 guidesHow to verify a SHA-256 checksum online
Confirm that a downloaded string or file content matches a known SHA-256 hash.
How to generate an MD5 hash online
Quickly compute an MD5 digest of a string for a legacy API or non-security checksum.
How to use SHA-256 for API request signing
Compute the SHA-256 canonical request hash required by AWS SigV4 and similar APIs.
How to choose between SHA-256 and SHA-512
Pick the right SHA-2 variant for a new security-sensitive application.
URL Encoder / Decoder
4 guidesHow to encode a URL query parameter value
Safely embed user input or special characters in a URL query string.
How to decode a percent-encoded URL
Convert %XX sequences back to human-readable text for debugging or display.
How to encode an OAuth redirect_uri parameter
Percent-encode a callback URL for use as an OAuth 2.0 redirect_uri query parameter.
How to fix malformed or double-encoded URLs
Diagnose and repair a URL that has been encoded twice or has broken percent sequences.
Unix Timestamp Converter
4 guidesHow to convert a Unix timestamp to a readable date
Turn an epoch seconds value from a database, API, or log file into a human-readable date.
How to convert a date to a Unix timestamp
Get the Unix epoch seconds for a specific date to use in a database, API, or JWT.
How to check a JWT expiry timestamp
Convert the 'exp' claim in a JWT payload from Unix seconds to a readable expiry date.
How to read a Unix timestamp in a log file
Convert a numeric timestamp from a log entry to a readable date for incident debugging.
UUID Generator
4 guidesHow to generate a UUID v4 online
Get a cryptographically random UUID instantly without installing any tools.
How to validate whether a string is a valid UUID
Check if an ID from an API response or user input matches the UUID format.
How to choose between UUID and auto-increment IDs
Decide when to use UUID primary keys vs sequential integer IDs in a database.
How to use a UUID as an idempotency key
Generate a UUID to use as an idempotency key for safe API request retries.
Text Case Converter
4 guidesHow to convert camelCase to snake_case
Convert JavaScript variable names to Python or SQL naming conventions.
How to convert snake_case to camelCase
Convert Python or database identifiers to JavaScript naming conventions.
How to convert identifiers to kebab-case for CSS and URLs
Convert variable names or phrases to the kebab-case convention used in CSS and URL slugs.
How to convert identifiers to PascalCase for class names
Convert snake_case or camelCase identifiers to PascalCase for React components and class names.
JSON to CSV Converter
4 guidesHow to convert a JSON API response to a CSV spreadsheet
Export API data to a CSV file for analysis in Excel or Google Sheets.
How to convert a CSV file to JSON
Parse a CSV export from a database or spreadsheet into a JSON array for use in code.
How to flatten nested JSON to CSV
Convert a JSON response with nested objects into a flat CSV table.
How to convert JSON to CSV in Python
Use the REST API or Python's csv module to convert JSON data to CSV programmatically.
Color Converter
4 guidesHow to convert HEX to RGB for CSS
Convert a HEX colour code from a design file to an rgb() value for use in CSS.
How to convert RGB to HEX
Convert an RGB colour value to a HEX code for use in HTML, CSS, or a design tool.
How to generate a colour palette using HSL
Use HSL values to programmatically generate tints, shades, and complementary colours.
How to convert colours programmatically via the REST API
Use the Color Converter API to convert HEX or RGB colours in a script or application.