php-simple-captcha
creates & verifies captcha images, dependency-free & respecting your user's privacy. It's a fork of Gregwar/Captcha
, but supports modern PHP versions and comes with several new features & bug fixes.
It's available for Composer:
composer require s1syphos/php-simple-captcha
Upon invoking the main class, you may specify a phrase (the string hidden in the captcha image), otherwise one will be created randomly:
<?php
require_once('vendor/autoload.php');
use SimpleCaptcha\Builder;
# First, you have to instantiate it ..
# (1) .. either this way ..
$builder = new Builder;
# (2) .. or this way
$builder = Builder::create();
# Now, building a captcha is easy
$builder->build();
If you want the generated phrase to be even more random, buildPhrase()
has your back:
# Create random phrase ..
# (1) .. consisting of 32 characters
# (2) .. being randomly chosen from 'abc@123'
$phrase = Builder::buildPhrase(32, 'abc@123');
# Now proceed like above ..
# (1) .. either this way ..
$builder = new Builder($phrase);
# (2) .. or this way
$builder = Builder::create($phrase);
From here, you can ..
(1) .. save the captcha to a file:
$builder->save('out.jpg');
# GIF & PNG are also supported, so this works too:
$builder->save('out.png');
$builder->save('out.gif');
# Optionally, quality may be specified:
# - JPG: 0-100
# - PNG: 0-9
$builder->save('low-quality.jpg', 40);
(2) .. output it directly in the browser:
# Default: JPG & 90
$builder->output();
# .. but how about ..
$builder->output(6, 'png');
(3) .. inline its data URI in your HTML:
<img src="https://github.com/S1SYPHOS/php-simple-captcha/raw/main/<?= $builder->inline() ?>" />
You'll be able to get the code and compare it with a user input:
# Example: storing the phrase in the session to test for the user input later
$_SESSION['phrase'] = $builder->phrase;
Note: Since one of the randomly selected fonts may contain letters looking very similar, you should validate user input using compare()
, otherwise you might end up with unsolvable captchas:
if ($builder->compare($input)) {
# Valid phrase
} else {
# Invalid phrase
}
From there, the following functions are available:
randomCharacter(string $charset = null): string
Picks random character (using given charset)
buildPhrase(int $length = 5, string $charset = null): string
Builds random phrase (of given length using given charset)
build(int $width = 150, int $height = 40): self
Builds captcha image
buildAgainstOCR(int $width = 150, int $height = 40): self
Builds captcha image until it is (supposedly) unreadable by OCR software
save(string $filename, int $quality = 90): void
Saves captcha image to file
output(int $quality = 90, string $type = 'jpg'): void
Outputs captcha image directly
fetch(int $quality = 90, string $type = 'jpg'): string
Fetches captcha image contents
inline(int $quality = 90, string $type = 'jpg'): string
Fetches captcha image as data URI
compare(string $phrase, string $string = null): bool
Checks whether captcha was solved correctly. Upon passing another string, both strings are compared (instead of first string & current phrase).
There are several settings you may use in order to change the behavior of the library:
$builder->phrase (string)
Captcha phrase. Default: random, see buildPhrase()
$builder->fonts (array)
Paths to captcha fonts. Default: Font files inside fonts
$builder->distort (bool)
Whether to distort the image. Default: true
$builder->interpolate (bool)
Whether to interpolate the image. Default: true
$builder->maxLinesBehind (int)
Maximum number of lines behind the captcha phrase. Default: random
$builder->maxLinesFront (int)
Maximum number of lines in front of the captcha phrase. Default: random
$builder->maxAngle (int)
Maximum character angle. Default: 8
$builder->maxOffset (int)
Maximum character offset. Default: 5
$builder->bgColor (array|string)
Background color, either RGB values (array), HEX value or 'transparent'
(string). Default: random
$builder->lineColor (array|string)
Line color RGB values (array) or HEX value (string)
$builder->textColor (array|string)
Text color RGB values (array) or HEX value (string)
$builder->bgImage (string)
Path to background image. Default: background fill, see bgColor
$builder->applyEffects (bool)
Whether to apply any effects. Default: true
$builder->applyNoise (bool)
Whether to apply background noise (using random letters). Default: true
$builder->noiseFactor (int)
Multiples of phrase length to be used for noise generation. Default: 2
$builder->applyPostEffects (bool)
Whether to apply post effects. Default: true
$builder->applyScatterEffect (bool)
Whether to enable scatter effect. Default: true
$builder->randomizeFonts (bool)
Whether to use random font for each symbol. Default: true
Have a look at the examples inside the demo
folder, which should give you an impression of what's possible - or simply whip up a PHP development server:
# Change directory
cd demo
# Launch server
php -S localhost:3000
# All examples are now available in your browser, eg 'http://localhost:3000/ocr.php'
The fonts
directory includes:
This library is based on Gregwar/Captcha
, introducing several new features & bug fixes.