# The Evolution of PHP: From 5.5 to 8.6

> Stop by stop, from generators to partial function application, what PHP gained in each release and how its type system was built layer by layer.

- Kind: Infographic
- Published: 2026-11-01
- Based on these articles: https://muhammetsafak.com/blog/traversing-large-datasets-with-php-55-generators-and-yield/ · https://muhammetsafak.com/blog/php-5-6-new-features-variadic-functions-and-exponentiation-operator/ · https://muhammetsafak.com/blog/php-7-0-the-long-awaited-release-speed-and-type-declarations/ · https://muhammetsafak.com/blog/scalar-type-declarations-and-return-types-in-php-7/ · https://muhammetsafak.com/blog/php-7-1-nullable-types-and-void-return-type/ · https://muhammetsafak.com/blog/php-72-and-modern-php-habits/ · https://muhammetsafak.com/blog/php-7-3-flexible-heredoc-and-list-assignments/ · https://muhammetsafak.com/blog/php-7-4-typed-properties-and-arrow-functions/ · https://muhammetsafak.com/blog/preparing-for-php-8-union-types-match-named-arguments/ · https://muhammetsafak.com/blog/coding-with-php-8-0-attributes-and-nullsafe-operator/ · https://muhammetsafak.com/blog/php-8-1-safer-domain-models-with-enums-and-readonly/ · https://muhammetsafak.com/blog/php-8-2-readonly-classes-and-new-types/ · https://muhammetsafak.com/blog/php-8-3-typed-class-constants-and-new-additions/ · https://muhammetsafak.com/blog/php-8-4-property-hooks-and-asymmetric-visibility/ · https://muhammetsafak.com/blog/php-85-on-the-way-the-languages-maturing-face/ · https://muhammetsafak.com/blog/php-8-6-on-the-way-the-languages-stable-evolution/
- Source: https://muhammetsafak.com/visuals/i/php-evolution-from-5-5-to-8-6/
- Language: en-US
- Author: Muhammet Şafak

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## The Evolution of PHP: From 5.5 to 8.6

PHP · Release by release

Stop by stop: what the language gained in each release.

Muhammet Şafak November 1, 2026

## Panel 2

Up to 2×

PHP 7.0 · Zend Engine 3

speed gain compared with PHP 5.6

According to the benchmark results on PHP.net, in real applications. The engine was rewritten; WordPress, Drupal and Magento tests also showed a clear improvement.

## From generators to typed properties

5.x and 7.x

1.   5.5 · generators and yield: values on demand, one at a time done
2.   5.6 · variadics (...), exponentiation (\*\*), constant expressions, use function done
3.   7.0 · Zend Engine 3, scalar and return types, <=>, ??, anonymous classes done
4.   7.1 · nullable types (?T) and the void return type done
5.   7.2 · object type (November 2017) done
6.   7.3 · flexible heredoc, short syntax in list assignments done
7.   7.4 · typed properties and arrow functions (November 2019) done

## From union types to partial function application

8.x

1.   8.0 · union types, match, named arguments, attributes, ?-> done
2.   8.1 · native enums and readonly properties done
3.   8.2 · readonly classes, DNF types (December 8, 2022) done
4.   8.3 · typed class constants, #\[\\Override\], json\_validate() done
5.   8.4 · property hooks and asymmetric visibility done
6.   8.5 · pipe operator (|>) done
7.   8.6 · partial function application, expected on November 19, 2026 pending

## Each gap closed by the next release

Function signature: untyped to typed

What was missing Each line is a gap the next release closed.

-   5.6: no scalar parameter types
-   5.6: no return types
-   7.0: a null return cannot be reflected in the return type
-   7.4: the signature accepts only one type per parameter

What arrived The signature tells you what the value is.

-   Scalar type declarations (7.0)
-   Return type declarations (7.0)
-   Nullable ?T and void (7.1)
-   Union types: int|string (8.0)

## Layer by layer

Type system

Each release built on the one before; at the very bottom, the scalar types of 7.0.

1.  Typed class constants 8.3
2.  DNF, standalone null / true / false 8.2
3.  readonly properties 8.1
4.  Union types 8.0
5.  Typed properties 7.4
6.  Scalar and return types, ?T, void, object 7.0 → 7.2

## The calendar is set in advance

PHP 8.6

-   September 22 hard feature freeze, 2026 Only bug fixes afterwards
-   November 19 expected release date, 2026 According to the release schedule
-   33 / 0 partial function application RFC vote The one visible syntax addition
-   39 / 3 warning for return from finally From the deprecation list

## Panel 8

> So there is nothing we learn in November — November only ships what was already settled in September.

Muhammet Şafak PHP 8.6 is on the way: the language's steady evolution

## The language took a step every year.

Steady evolution

[muhammetsafak.com/blog/php-8-6-on-the-way-the-languages-stable-evolution/](https://muhammetsafak.com/blog/php-8-6-on-the-way-the-languages-stable-evolution/)

One minor release every year since 2020; the last four releases fell between November 19 and 23.