After initial investigation into Rector performance 🏎️, we are now at a point where we need more detailed data to get it even faster. That’s why we added more debug information to the Rector output - inspired by Ruud Kamphuis script to find slowest PHPStan files.

You want to look into PHPStan performance instead?

How to find out why Rector is slow on your project?

Requires Rector 0.16.1 or later - not yet released

First we need a single run across the whole project which collects some useful information we can later look into:

vendor/bin/rector -vvv --debug --no-diffs | tee rector.log

Analyse the generated rector.log file with parse.php1:

php parse.php

Now you get a list of files sorted by the time it took Rector to refactor which looks like:

Slowest files
4.90 seconds: [file] packages/Testing/PHPUnit/AbstractRectorTestCase.php
4.07 seconds: [file] packages/FamilyTree/Reflection/FamilyRelationsAnalyzer.php
2.99 seconds: [file] packages/Caching/ValueObject/CacheFilePaths.php
2.95 seconds: [file] packages/BetterPhpDocParser/Attributes/AttributeMirrorer.php
2.93 seconds: [file] packages/BetterPhpDocParser/PhpDocNodeVisitor/TemplatePhpDocNodeVisitor.php
2.68 seconds: [file] packages/FamilyTree/Reflection/FamilyRelationsAnalyzer.php
2.61 seconds: [file] packages/NodeTypeResolver/TypeAnalyzer/ArrayTypeAnalyzer.php
2.53 seconds: [file] packages/PHPStanStaticTypeMapper/TypeMapper/OversizedArrayTypeMapper.php
2.07 seconds: [file] packages/BetterPhpDocParser/ValueObject/PhpDocAttributeKey.php
1.71 seconds: [file] bin/clean-phpstan.php
1.52 seconds: [file] config/set/php80.php
1.18 seconds: [file] packages/PhpAttribute/NodeAnalyzer/ExprParameterReflectionTypeCorrector.php
1.01 seconds: [file] packages/Testing/PHPUnit/AbstractRectorTestCase.php
0.97 seconds: [file] config/set/php52.php
0.89 seconds: [file] packages/BetterPhpDocParser/PhpDocNodeVisitor/TemplatePhpDocNodeVisitor.php
0.83 seconds: [file] packages/PHPStanStaticTypeMapper/TypeMapper/ResourceTypeMapper.php
0.83 seconds: [file] packages/Caching/ValueObject/Storage/MemoryCacheStorage.php
0.78 seconds: [file] config/set/php80.php
0.69 seconds: [file] packages/PhpAttribute/AnnotationToAttributeMapper/ArrayItemNodeAnnotationToAttributeMapper.php
0.63 seconds: [file] packages/StaticTypeMapper/PhpDocParser/NullableTypeMapper.php
0.62 seconds: [file] rules/CodingStyle/Rector/ClassConst/VarConstantCommentRector.php
0.60 seconds: [file] packages/PhpAttribute/NodeAnalyzer/ExprParameterReflectionTypeCorrector.php
0.56 seconds: [file] packages/PhpAttribute/AnnotationToAttributeMapper/ArrayItemNodeAnnotationToAttributeMapper.php

Starting from here you can use your favorite profiler to analyse only the slowest files in isolation.

Example with blackfire and the path to a slow file:

blackfire run --ignore-exit-status php vendor/bin/rector -vvv --debug --no-diffs packages/Testing/PHPUnit/AbstractRectorTestCase.php

If performance analysis is not your thing, feel free to open an issue on Rector and bring with you all the information you already gathered in the above process. Its important you bring all files and configs required to reproduce your performance issue as part of the report.

In case you support my engagement with a GitHub sponsoring, I can have a look at your performance problem.

parse.php script

<?php // parse.php

// inspired and adopted from

$log = new SplFileObject("rector.log");

$logs = [];
$file = null;
while (! $log->eof()) {
    $line = trim($log->fgets());
    if ($line === '') {

    if (str_starts_with($line, '[file]')) {
        $file = $line;

    if ($file === null) {
    if (preg_match('/took (?<seconds>[\d.]+) s/', $line, $matches) === 1) {
        $accu = 0.0;
        if (array_key_exists($file, $logs)) {
            $accu = $logs[$file][0];
        $logs[$file] = [$accu + ((float) $matches['seconds']), $file];
        $file = null;

usort($logs, fn(array $left, array $right) => $right[0] <=> $left[0]);
$logs = array_slice($logs, 0, 100);

echo "Slowest files" . PHP_EOL;
foreach ($logs as $log) {
    echo sprintf("%.2f seconds: %s", $log[0], $log[1]) . PHP_EOL;
  1. Script to analyse and sort the rector.log 

Found a bug? Please help improve this article.

Previous Post
Racing Rector
Next Post
Doctor Rst Speedup