Java Developer Utilities
Java remains the backbone of enterprise software, from Spring Boot microservices to Android apps to massive data-processing pipelines. The daily grind of formatting JSON, testing regex patterns, converting between data formats, and debugging timestamps costs valuable minutes. These free, browser-based tools let you handle those tasks instantly without firing up an IDE plugin.
JSON Formatter & Validator
Paste raw or minified JSON from a REST endpoint and get a pretty-printed, syntax-highlighted view. The validator catches structural errors — missing commas, unclosed braces — before they trigger a JsonParseException in Jackson or Gson.
JSON to XML Converter
Enterprise integrations, SOAP services, and legacy systems still speak XML. Convert JSON payloads to well-formed XML when bridging modern microservices with older middleware — no XSLT required.
JSON to YAML Converter
Convert JSON configuration to YAML for Spring Boot application.yml, Kubernetes manifests, or Helm charts. One click replaces tedious manual reformatting.
RegExp Tester
Java's java.util.regex can be verbose. Test patterns against sample strings with real-time highlighting before embedding them in Pattern.compile(). Eliminates the compile-run-check cycle.
Base64 Encoder / Decoder
Decode JWTs, encode binary payloads for API calls, or inspect java.util.Base64 output. Essential when working with authentication tokens, SAML assertions, and data: URIs.
Code Diff Tool
Compare two versions of a Java class, a pom.xml change, or a Gradle build script side by side. Quicker than running git diff when you just need a fast visual comparison.
MD5 / Hash Generator
Generate MD5, SHA-256, and SHA-512 hashes to verify JAR checksums, test MessageDigest output, or debug HMAC signatures in API integrations.
URL Encoder / Decoder
Encode query parameters for HttpURLConnection or decode percent-encoded strings from servlet request logs. Prevents the classic double-encoding bug.
Timestamp Converter
Convert Unix epoch milliseconds to human-readable dates and back. Critical when reading application logs, debugging Instant.ofEpochMilli() values, or comparing timestamps across distributed systems.
Hex Converter
Convert byte arrays to hex strings for debugging binary protocols, cryptographic digests, and raw socket data in Java networking code.
Crontab Calculator
Validate cron expressions for Spring @Scheduled tasks or Quartz Scheduler jobs. See the next ten execution times so your batch jobs fire exactly when expected.
AES Encryptor
Test AES encryption and decryption to verify your javax.crypto.Cipher implementation. Useful for debugging encrypted configuration values and validating key/IV combinations.
Password Generator
Generate strong random passwords for service accounts, database credentials, and application.properties secrets. Avoids the temptation of reusing weak passwords across environments.