Is this JSON valid and readable?
Validate the syntax, expose the structure with indentation, and use the error location to fix malformed input. Open JSON formatter & validator
Code drawer
Developer tools
Format, inspect, convert, and generate the small things that slow down development.
Choose a job
What do you need to do?
Developer
JSON formatter & validator
Validate JSON, format it with readable indentation, or minify it for transport.
Developer
JSON diff
Compare two JSON values after normalizing their formatting.
Developer
YAML ↔ JSON converter
Convert configuration data between YAML and JSON in either direction.
Developer
CSV ↔ JSON converter
Convert a header-based CSV table to JSON records or JSON records back to CSV.
Developer
Base64 & URL encoder
Encode and decode plain text using Base64 or URL percent-encoding.
Developer
UUID generator
Generate one or many cryptographically random version 4 UUIDs.
Developer
JWT decoder
Decode a JSON Web Token header and payload into readable JSON.
Developer
Regex tester
Test a JavaScript regular expression against sample text with flags and match details.
Developer
UTM campaign URL builder
Add consistent source, medium, campaign, term, and content parameters to a URL.
Developer
Markdown preview
Write Markdown and see the rendered document update beside it.
DeveloperNew
Number base converter
Convert whole numbers between binary, octal, decimal, and hexadecimal.
DeveloperNew
HTML entity encoder
Escape text for safe use in HTML, or decode entity references back to characters.
DeveloperNew
Password generator
Generate strong random passwords with your choice of length and character sets.
DeveloperNew
File checksum verifier
Calculate SHA-256, SHA-384, and SHA-512 checksums and compare against an expected value.
What this collection covers
The jobs these tools handle
These are the interruptions between real work: JSON that arrived on one line, a token you need to read the claims out of, an ID to generate, two files that differ somewhere. Format and validate JSON, diff two payloads, convert between YAML and JSON, decode base64 and URLs, build a tagged campaign link, generate UUIDs, and preview Markdown as it will render.
Choose the developer tool by the question you are answering
First identify whether the problem is invalid syntax, an unexpected difference, or a format mismatch. Each has a narrower tool than a general-purpose editor.
What changed between two JSON values?
Compare parsed values so key order and formatting do not hide the meaningful additions, removals, or edits. Open JSON diff
Does another system require YAML or JSON?
Convert the data model between formats, then review types and values before replacing a configuration file. Open YAML ↔ JSON converter
Review a changed configuration safely
Work with redacted data, validate both versions, and compare their parsed meaning before copying a result into a project.
1. Validate the original
Confirm the baseline parses successfully so an old syntax error is not mistaken for a new change. Open JSON formatter & validator
2. Normalize the format
Convert only when the two inputs use different serializations and keep a copy of each source. Open YAML ↔ JSON converter
3. Inspect semantic changes
Compare the normalized values and review each changed path before accepting the update. Open JSON diff
Privacy-first by design
Your work stays with you
Selected files and entered text stay private while you use these tools.
Smooth results
Tips for larger files
Very large files can need more memory, especially on a phone. Keep originals, start with a small batch, and close other heavy apps or tabs if a tool feels slow.