Tools for the Spring and Java ecosystem
9 small utilities that each do one job properly. Everything runs in your browser — no sign-up, no uploads, and safe to use on a config that still holds credentials.
Configuration
Reading and rewriting what Spring Boot loads at startup.
Properties ↔ YAML
Converts application.properties to application.yml and back, keeping indexed lists, escapes and value types intact.
Properties → env vars
Turns configuration keys into environment variables, Docker Compose, Kubernetes env or CLI arguments.
Log pattern tester
Previews a logging.pattern.console string against sample log lines, with %clr, width modifiers and logger abbreviation.
Runtime
Behaviour that only shows itself once the application is running.
Cron expression parser
Explains a @Scheduled expression in plain English and lists its next runs. Six fields, with L, W and #.
Ant path matcher
Tests what a path pattern really matches, extracts path variables, and flags patterns Spring 6 rejects.
Bean Validation tester
@NotNull, @NotEmpty and @NotBlank side by side against every value, plus the null rule that makes @Size optional.
Security
The settings that decide who gets in.
Persistence
What the database ends up being called.
Build
Moving between build tools.
Boards
Collected every morning rather than driven by what you paste in.
Why another tools site
There is no shortage of pages offering a JSON formatter and a Base64 encoder side by side. Almost none of them know anything about Spring, so they flatten a properties file on the first= they find and call it done. These tools are built around how Spring Boot actually reads configuration, which is where the awkward cases live — the six-field cron that Unix tools get wrong, the dash that disappears in an environment variable, the* that should have been **.