DevCoreTools Learn

Practical guides for developer formats and debugging workflows

Understand, validate, transform, and debug common developer data formats and patterns with confidence, using the right tool for the job in front of you.

Start here

Quick entry points

{}JSONRead the JSON guide.JWTJWT & API AuthRead the JWT & API Auth guide..*RegexRead the Regex guide.SQLSQLRead the SQL guide.<>HTML & WebRead the HTML & Web guide.CRONDevOps & CronRead the DevOps & Cron guide.<>Data ConversionRead the Data Conversion guide.KEYSecurity & CryptoRead the Security & Crypto guide.

Explore by topic

Guide categories

Live guides open full documentation pages. Next and planned areas point to the best tools today.

{} Live

JSON

Understand JSON syntax, validation, schema checks, JSONPath, structural diffs, and conversions.

JSON Formatter JSON Validator JSON Minifier JSON Diff+ 6 more tools

Read the JSON guide

JWT Live

JWT & API Auth

Decode claims, verify signatures, inspect timestamps, and handle API authentication values safely.

JWT Decoder JWT Verifier Base64 Encoder/Decoder Unix Timestamp Converter+ 2 more tools

Read the JWT & API Auth guide

.* Live

Regex

Test expressions, flags, capture groups, and text changes before placing patterns in code.

Regex Tester Text Diff Checker HTML Entity Encoder/Decoder JSON Validator+ 1 more tools

Read the Regex guide

SQL Live

SQL

Format, review, and clean up SQL queries for debugging, code review, and documentation.

SQL Prettifier

Read the SQL guide

<> Live

HTML & Web

Inspect browser-facing markup, scripts, styles, entities, previews, and web-safe text.

HTML Formatter / Beautifier HTML Previewer / Live HTML Preview HTML Minifier HTML Entity Encoder/Decoder+ 5 more tools

Read the HTML & Web guide

CRON Live

DevOps & Cron

Read cron schedules, convert timestamps, and validate configuration-adjacent data.

Cron Expression Generator Cron Expression Parser / Explainer Unix Timestamp Converter

Read the DevOps & Cron guide

<> Live

Data Conversion

Move data between JSON, CSV, YAML, and XML while checking shape and type assumptions.

JSON to CSV CSV to JSON JSON to YAML YAML to JSON+ 1 more tools

Read the Data Conversion guide

KEY Live

Security & Crypto

Generate hashes, HMACs, and passwords, and inspect token-related security values locally.

Hash Generator HMAC Generator Password Generator JWT Decoder+ 3 more tools

Read the Security & Crypto guide

Popular tools

Jump straight to a utility

{}JSON FormatterJWTJWT Decoder .*Regex TesterSQLSQL Prettifier CRONCron Expression Parser / Explainer {}JSON Validator64Base64 Encoder/Decoder

Practical & focused

Step-by-step guides that get you to the right utility quickly.

Hands-on examples

Real workflow examples you can copy, compare, and try.

Trusted/local-first

Guidance aligned with browser-based tools and careful data handling.

Always improving

New guides and tools added as common developer workflows grow.