PHP Version Compatibility Checker

How it works

What it does

The Compatibility Checker scans pasted PHP for constructs and APIs that differ across PHP versions. It helps you plan upgrades—for example from older 7.x lines toward modern 8.x—by highlighting syntax and known compatibility pitfalls that static rules can detect.

It is a planning aid, not a guarantee that an application will pass full test suites on a new runtime.

When to use it

• Before bumping config.platform.php or CI images
• When reviewing a legacy module that has not been touched in years
• To gather talking points for a migration checklist
• Alongside deprecated-function findings for a fuller picture

How input is processed safely

Rules run as static analysis on text. No arbitrary execution, no Composer installs, and no remote code fetch. Findings are based on known language/engine differences represented in the tool’s rule set—not by running your code under multiple PHP binaries on this host.

Examples

• Flagging dynamic properties patterns relevant to PHP 8.2+
• Noting removed or changed language features in a pasted function
• Highlighting curly-brace string/array access styles that newer engines reject

Common mistakes

• Treating “no findings” as proof the whole project is upgrade-ready
• Scanning only one file while vendor packages dominate the risk
• Ignoring extension availability (ext-*) which this snippet scanner cannot inventory from code alone

Upgrade risk usually concentrates in a few areas: removed SAPIs/extensions, changed default error behavior, stricter types, and dormant deprecations that become errors. Static snippet scanning catches many language-level issues early, but integration tests remain mandatory for database drivers, encoding, and framework bootstraps.

Use this checker together with the deprecated checker and your Composer platform constraints. A green snippet scan plus a green composer.json platform section still does not replace running the test suite on the target PHP image.

When you find a hit, open the related ZendStudio.net error/migration guides linked from the tools hub. Fixing one representative file often reveals a mechanical pattern you can apply across the codebase with search tooling.

Privacy note

Avoid pasting proprietary algorithms or credentials. Prefer representative samples. Pair results with local PHPUnit/Psalm runs inside your own environment.

Safety notes

• Submitted tool contents are not written to analytics or search logs.
• This site never evaluates arbitrary PHP from the browser.
• Generated configs are starting points—validate on a staging host before production.