Browser-local developer toolbox
Useful developer tools without uploading your data
Format payloads, inspect tokens, generate identifiers, and convert common developer data directly in your browser.
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Core tools
62 utilities available through hubs and search
JSON Formatter Online – Format & Beautify JSON
Format and beautify JSON locally with 2-space, 4-space, or tab indentation, optional key sorting, syntax checks, and no uploads.
Runs locallyJSON Validator Online – Check JSON Syntax
Validate JSON syntax locally, find errors with line and column details, and check API payloads without uploading data.
Runs locallyRegex Tester Online – Test, Match & Replace
Test JavaScript regular expressions, inspect all matches and capture groups, or replace text locally in your browser with configurable regex flags.
Runs locallyCase Converter Online – Change Text Case
Convert text to uppercase, lowercase, Sentence case, Title Case, camelCase, PascalCase, snake_case, CONSTANT_CASE, dot.case, kebab-case, or URL slugs locally in your browser.
Runs locallyBase64 Encoder & Decoder Online
Encode UTF-8 text or hexadecimal bytes to Base64, create unpadded URL-safe Base64 (Base64URL), and decode either variant as UTF-8 text or hexadecimal bytes locally in your browser.
Runs locallyJWT Decoder Online
Decode JWT header and payload JSON locally, inspect exp, nbf, and iat time status, and remember that the signature is not verified.
Runs locallyUUID Generator & Validator Online
Generate UUID v4 or time-ordered UUID v7 batches, validate canonical UUID format and version, and decode embedded UUID v7 timestamps locally.
Runs locallyUnix Timestamp Converter Online
Convert Unix timestamps in seconds and milliseconds, plus common 16-digit microseconds and 19-digit nanoseconds, to readable dates locally in your browser.
Runs locallyMore JSON workflows
Repair broken JSON, locate syntax errors, convert data, or generate typed models for TypeScript and Go.
Topics & categories
Browse by topic
JSON & Data Tools
Format, compare, validate, convert, and query structured data without sending it to a server.
Text & CodeText & Code Tools
Test regular expressions and convert text between common code-friendly naming styles locally.
Encoding & SecurityEncoding & Security Tools
Inspect tokens, encode text as Base64 or hex, transform URL or HTML components, and create common digests locally.
Identifiers & TimeIdentifier & Time Tools
Generate UUIDs, convert timestamps, and calculate IPv4 address ranges in your browser.
JSON topicJSON Tools, Validators, Converters & Troubleshooting
Explore JSON tools, validators, converters, error fixes, schema utilities, and developer guides in one automatically maintained topic hub.
Regular Expressions topicRegex Tools, Tester, Examples & Pattern Troubleshooting
Explore browser-local regex testers, matchers, replacers, pattern examples, common JavaScript regex errors, and a quick-reference guide in one place.
New & updated
Recently updated across VetaTool
JSON Formatter Online – Format & Beautify JSON
Format and beautify JSON locally with 2-space, 4-space, or tab indentation, optional key sorting, syntax checks, and no uploads.
Tool · Updated 2026-10-12CSV to SQL Converter – Generate MySQL INSERT Statements
Convert CSV to MySQL INSERT statements in your browser. Edit column names, choose batch size, and safely escape quotes without uploading your data.
Tool · Updated 2026-10-12Docker Run to Compose Converter – Generate compose.yaml Online
Convert a docker run command into Compose Specification YAML locally. Map ports, volumes, environment, networks and restart settings without running Docker.
Tool · Updated 2026-10-12HMAC SHA-256 Generator Online – Sign Messages Locally
Generate HMAC-SHA256 from a secret key and message locally. Choose UTF-8, Hex or Base64 bytes; copy Hex/Base64 signatures without uploading secrets.
Developer guides
Learn the workflow, not just the syntax
JavaScript Regex Cheat Sheet – Quick Reference & Examples
JavaScript regex quick reference for character classes, anchors, quantifiers, groups, lookarounds, flags, replacements, and copyable examples.
7 min readHow to Fix Invalid JSON Errors
Learn how to find and fix missing commas, unquoted keys, trailing commas, invalid escapes, hidden characters, and other common JSON errors.
6 min readJSON vs JSONL: Differences and Examples
Compare JSON and JSONL structure, examples, streaming behavior, error handling, and the situations where each format is the better choice.
6 min readBase64 vs Base64URL: What Changes?
Understand the Base64URL alphabet, padding rules, JWT usage, UTF-8 decoding, and how to convert safely between standard Base64 and URL-safe Base64.
Solve a problem
Debug common developer errors
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