# YAK Pro PHP Obfuscator: setup, configuration, and limits

> YAK Pro transforms pure PHP source into harder-to-read code for developers distributing PHP applications. It supports recursive processing and incremental obfuscation, but it excludes mixed HTML and PHP files and has inconsistent PHP-Parser setup instructions.

**pk-fr/yakpro-po** — YAK Pro - Php Obfuscator

- Repository: https://github.com/pk-fr/yakpro-po
- Website: http://www.php-obfuscator.com
- Stars: 1,585 · Forks: 414
- Language: PHP
- License: NOASSERTION
- Published: 2026-10-16 · Updated: 2026-10-16 · Language: en
- Canonical page: https://hysenlabs.com/projects/pk-fr-yakpro-po

## Why YAK Pro targets distributed PHP source

YAK Pro addresses a specific distribution problem. Because the PHP runtime interprets application code, distributing a PHP application normally means distributing its source. The README says recipients can otherwise read, modify, or adapt that implementation. YAK Pro transforms PHP source into a form intended to remain executable by PHP while becoming harder for people to understand.

The intended users are developers who distribute pure PHP projects and need a command-line transformation rather than an online service or hosted application. The documented features include removing comments and indentation, generating a single-line PHP file, obfuscating string literals, changing control-flow constructs, scrambling identifiers, and shuffling statements. Identifier renaming can cover variables, functions, constants, classes, interfaces, traits, properties, methods, namespaces, and labels.

This is a source transformation tool, not a PHP compiler, deployment service, or general-purpose source-code security scanner. It changes program text, but the README does not claim that the output protects secrets, prevents all reverse engineering, or guarantees resistance to automated deobfuscation. Its practical purpose is to raise the cost of reading and adapting distributed PHP code.

YAK Pro also accounts for multi-file projects. It can recursively process source directories, preserve selected files or directories, exclude source files from the output, and retain specified names or name prefixes. Those controls are relevant to teams that cannot simply transform every file uniformly.

## How PHP-Parser enables YAK Pro transformations

YAK Pro parses PHP through PHP-Parser rather than applying unrestricted text replacement. The README identifies PHP-Parser 5.x for YAK Pro 3.x. This parser-based foundation allows the tool to recognize PHP constructs and rewrite them while preserving a valid PHP structure. The listed control-flow targets include if, else, elseif, for, while, and do while, which YAK Pro can rewrite into if goto statements.

The pipeline also includes identifier renaming, string-literal obfuscation, and statement shuffling. Name changes must remain consistent across a project because renamed functions, classes, methods, properties, and namespaces can refer to one another. For directory processing, the README says context is saved so the tool can reuse the same obfuscation translation table. Without that shared mapping, a renamed class in one file could become inconsistent with references in another.

The tool recursively reads a source directory and writes the transformed tree under the target directory’s yakpro-po subdirectory. It also documents a Makefile-like timestamp mechanism that limits re-obfuscation to files changed since the previous run. This incremental design is useful when repeatedly processing a larger project, although the README does not provide detailed guidance for recovering or reconciling partial output.

Configuration determines which transformations are enabled. The repository’s yakpro-po.cnf is described as self-documented and offers many controls over obfuscation. Operators should treat that file, rather than the overview in the README, as the source for exact option names, defaults, exclusions, and preserved names.

## Installing YAK Pro 3.x and resolving PHP-Parser

The setup requires git and php-cli. The README also says to install any other PHP modules used by the software being obfuscated, giving php-mysql as an example when MySQL is used. The following commands are copied from the documented Ubuntu setup:

```bash
# apt install git
# apt install php-cli
```

The README uses /usr/local as an example installation location and retrieves YAK Pro from GitHub:

```bash
# cd /usr/local
# git clone https://github.com/pk-fr/yakpro-po.git
```

After cloning, it instructs users to enter the project directory. However, the setup section gives a PHP-Parser 4.x clone command while the 3.x warning explicitly says that PHP-Parser 5.x is required. This inconsistency must be resolved before adoption.

```bash
# cd yakpro-po
# git clone https://github.com/nikic/PHP-Parser.git --branch 4.x
```

The README says YAK Pro 3.x runs on PHP 7.4 or higher and can obfuscate code for PHP 7.0 through PHP 8.x. It associates PHP-Parser 5.x with 3.x, PHP-Parser 4.x with the unsupported 2.x branch, and PHP-Parser 1.x with the unsupported 1.x branch. Because the setup command conflicts with the 3.x prerequisite, users should verify the dependency state for the exact branch they intend to run rather than assume the documented 4.x clone is correct.

The remaining setup steps make the PHP entry point executable and create a symbolic link in /usr/local/bin:

```bash
# chmod a+x yakpro-po.php
# cd /usr/local/bin
# ln -s /usr/local/yakpro-po/yakpro-po.php yakpro-po
```

After installation, --help is the documented first command. A readable help response confirms that the symlink reaches the entry point. The README does not document a dependency verification command for resolving the PHP-Parser conflict.

## Running the first file and directory obfuscations

A basic first use sends the transformed source to standard output:

```bash
# yakpro-po --help
# yakpro-po test.php
```

The first command displays command information, while the second obfuscates the named file without an explicit output path. This is the simplest way to check whether the executable and its PHP dependency can load.

To write one transformed file, use the documented source and target arguments:

```bash
yakpro-po source_filename -o target_filename
```

For a project tree, the command follows the same source-to-target pattern and recursively processes the directory. According to the README, YAK Pro creates the target location if it does not exist and places output under target_directory/yakpro-po.

```bash
yakpro-po source_directory -o target_directory
```

Before adopting the tool, inspect the transformed source and run the receiving application’s normal syntax and functional checks. The README does not document an automated rollback command for failed transformations, nor does it define a verification suite for generated output. It does document --clean for an existing configured target, but this removes the recursively generated yakpro-po directory rather than validating or restoring a release.

```bash
yakpro-po --clean
```

A first real use should therefore be limited to representative PHP files, preserve the original tree, and verify that the resulting application behaves correctly. This matters because control-flow rewriting, statement shuffling, and cross-file name changes can affect more than formatting.

## Configuration loading, parser changes, and mixed-content limits

YAK Pro supports explicit and environment-based configuration. The first configured source is selected through the --config-file argument, then YAKPRO_PO_CONFIG_FILE when it exists and is not empty. If neither supplies a path, the tool uses YAKPRO_PO_CONFIG_FILENAME when available and otherwise looks for yakpro-po.cnf. If no file is found, the README says default values are used.

```bash
yakpro-po --config-file config_file_path
```

The configuration filename is searched under YAKPRO_PO_CONFIG_DIRECTORY when set, followed by the current working directory, its config subdirectory, the home directory, its config subdirectory, /usr/local/YAK/yakpro-po, and the source directory’s default configuration filename. This search order allows a command-line path to override environment-based and conventional locations. It also means operators should account for inherited environment variables when diagnosing unexpected settings.

The README warns users not to modify the repository’s yakpro-po.cnf directly because an update can overwrite it. A project-specific copy is the safer location. This matters especially because 3.x changed the parser_mode values. The former PREFER_PHP7, PREFER_PHP5, ONLY_PHP7, and ONLY_PHP5 choices have been replaced by HOST_VERSION, NEWEST_VERSION, or a version number such as 8.1. Users moving an existing configuration must revise that setting rather than carry forward the old syntax.

The clearest functional limitation is file scope. YAK Pro is written for pure PHP source and is not intended for HTML with embedded PHP. The README says users may try embedded HTML at their own risk and may need to deactivate statements shuffling. It does not document reliable support for templates, arbitrary mixed-language files, or the full range of syntax found in template-heavy applications.

YAK Pro also differs from an ordinary minifier. A source minifier can remove comments and indentation while retaining identifiers and control flow. YAK Pro can rename symbols, rewrite control flow, obfuscate strings, and shuffle statements. Those changes provide a greater readability barrier but also make configuration review and application-level validation more important.

## YAK Pro releases, repository status, and license review

The repository is not archived, and its last push was on 2026-05-16. The listed versions are 2.0.15 on 2025-01-28, 2.0.16 on 2025-03-10, and 2.0.17 on 2025-09-11. The README itself is titled for 3.x, while the listed releases belong to the 2.x line. This difference is another reason to identify the branch and release being adopted before following installation or configuration instructions.

Upgrade cost is concentrated in compatibility checks. Moving from 2.x to 3.x involves a different PHP-Parser generation and changed parser_mode values. Operators must revise existing configurations and ensure that the PHP runtime meets the documented PHP 7.4 minimum for 3.x. The project also directs users of older PHP inputs toward unsupported 1.x or 2.x branches, which means the correct tool depends on both the runtime used for obfuscation and the PHP versions targeted by the output.

The README describes YAK Pro as open source under the MIT License, but the repository metadata identifies a custom license that GitHub cannot classify and the repository includes LICENSE.md. The repository description and README therefore do not provide a sufficiently consistent basis for redistribution decisions. Teams should read the actual LICENSE.md file and resolve its terms before shipping generated software. This is a project-specific compliance check, not a legal conclusion.

Compared with a plain PHP minifier, YAK Pro adds parser-based transformations and recursive incremental processing, but it also introduces more failure points. It is appropriate when readable source distribution is the concern and pure PHP is an accepted input boundary. It is inappropriate when mixed templates dominate, when reproducible dependency setup is mandatory without resolving the documented conflict, or when license terms remain unclear.

## Conclusion

YAK Pro fits developers distributing pure PHP source who need configurable renaming, control-flow rewriting, and incremental directory processing. It is a poor fit for mixed HTML and PHP files, teams that cannot resolve the documented PHP-Parser dependency conflict, or organizations that need an unambiguous license classification before redistribution. Verify PHP-Parser compatibility, read LICENSE.md, and inspect generated output before adopting it.

## FAQ

### What PHP version does YAK Pro require?

The README says YAK Pro 3.x runs on PHP 7.4 or higher and can obfuscate code for PHP 7.0 through PHP 8.x. It points users with older requirements toward the unsupported 2.x or 1.x branches.

### Which version of PHP-Parser should I install for YAK Pro 3.x?

The README identifies PHP-Parser 5.x as the 3.x prerequisite, but its setup section says to clone the 4.x branch. The documented instructions conflict, so the dependency requirement should be verified before installation.

### Can YAK Pro obfuscate a PHP file with embedded HTML?

The README says YAK Pro is intended for pure PHP source, not HTML with embedded PHP. It mentions trying embedded HTML at the user’s own risk and possibly disabling statements shuffling.

### How does YAK Pro choose its configuration file?

The first available source is selected through --config-file, YAKPRO_PO_CONFIG_FILE, YAKPRO_PO_CONFIG_FILENAME, or the default yakpro-po.cnf filename. The selected filename is then searched across the documented project, home, installation, and source directories.

### Does YAK Pro reprocess every file during each directory run?

The README describes a timestamp-based mechanism that re-obfuscates changed files only. For directories, it also saves context so the same obfuscation translation table can be reused across files.

## Sources

- [Issues](https://github.com/pk-fr/yakpro-po/issues)
- [pk-fr/yakpro-po on GitHub](https://github.com/pk-fr/yakpro-po)
- [Project website](http://www.php-obfuscator.com)
- [README](https://github.com/pk-fr/yakpro-po/blob/master/README.md)
- [Releases](https://github.com/pk-fr/yakpro-po/releases)

---

Hysen Labs editorial analysis, written from the project's own repository and release notes. Cite the canonical page: https://hysenlabs.com/projects/pk-fr-yakpro-po