CodeIgniter Home
- What is CodeIgniter?
- Features of CodeIgniter
- Advantages over other PHP frameworks
- CodeIgniter version history
CodeIgniter Overview
- Key Components of CodeIgniter
- MVC design pattern explained
- Workflow of a CodeIgniter application
- System and Application folders overview
CodeIgniter Installing CodeIgniter
- System Requirements (PHP, MySQL, Extensions)
- Downloading & Extracting CodeIgniter
- Folder structure explained
- Setting base URL
- Configuring index.php file
- Running first application
CodeIgniter Application Architecture
- Folder structure in detail
- Application vs System folders
- Config, Controllers, Models, Views
- Helpers and Libraries placement
- User Guide access
CodeIgniter MVC Framework
- Understanding MVC flow
- Codeigniter Creating Controllers
- Creating Views
- Creating Models
- Loading Models and Views
- Data flow between MVC components
CodeIgniter Basic Concepts
- URLs in CodeIgniter
- Default controller setup
- Routing basics
- Auto-loading resources
- Naming conventions
CodeIgniter Configuration
- Configuration files overview
- Base URL and Index page settings
- Encryption key setup
- Codeigniter Database configuration
- Error logging configuration
- Custom configuration files
CodeIgniter Working with Database
- Database configuration
- Loading database library
- Query Builder class
- Running queries (select, insert, update, delete)
- Active Record class
- Transactions
- Joins, Grouping, Ordering, Limit
- Query bindings
- Result handling (row(), result())
CodeIgniter Libraries
- Built-in libraries overview
- Loading libraries
- Common libraries: Pagination, Upload, Email, Form Validation, Session, Encryption, Calendar
- Creating custom libraries
CodeIgniter Error Handling
- Error reporting levels
- Custom error pages (404, 500)
- Using log_message()
- Displaying errors in development vs production
CodeIgniter File Uploading
- Upload library setup
- File upload configuration (path, allowed types, max size)
- Handling errors in upload
- Multiple file uploads
- Securing uploads
CodeIgniter Sending Email
- Email library configuration
- Sending emails via SMTP
- Sending attachments
- Sending HTML emails
- Debugging email errors
CodeIgniter Form Validation
- Form validation library overview
- Setting validation rules
- Prepping data before validation
- Error messages customization
- Validation callbacks
- Server-side vs Client-side validation
CodeIgniter Session Management
- Session library configuration
- Storing session data
- Retrieving session data
- Flashdata in sessions
- Database-driven sessions
CodeIgniter Flashdata
- What is Flashdata?
- Creating flashdata messages
- Retrieving flashdata
- Flashdata expiration
CodeIgniter Tempdata
- Difference between flashdata & tempdata
- Creating tempdata
- Retrieving tempdata
- Removing tempdata
CodeIgniter Cookie Management
- Setting cookies
- Retrieving cookies
- Deleting cookies
- Cookie security
CodeIgniter Common Functions
- base_url()
- site_url()
- redirect()
- form_open() & form helper functions
- String helper functions
CodeIgniter Page Caching
- Enabling page caching
- Cache expiration
- Deleting cache files
- Best practices in caching
CodeIgniter Page Redirection
- Redirect helper function
- Permanent vs Temporary redirection
- Redirect with flashdata
CodeIgniter Application Profiling
- Enabling profiler
- Profiler sections (benchmarks, queries, post data, etc.)
- Customizing profiler output
CodeIgniter Benchmarking
- Benchmark class usage
- Measuring script execution time
- Measuring memory usage
- Custom benchmarks
CodeIgniter Adding JS and CSS
- Loading assets in views
- Using base_url() for assets
- Best practices for assets organization
- Versioning assets
CodeIgniter Internationalization
- Language files in CodeIgniter
- Loading language files
- Switching languages dynamically
- Multi-language website structure
CodeIgniter Security
- Input filtering and XSS cleaning
- CSRF protection
- SQL Injection prevention
- Password hashing & encryption
- Secure file uploads
- Using HTTPS with CodeIgniter

System Requirements (PHP, MySQL, Extensions)

Last modified on: September 7, 2025

<h1 data-start="499" data-end="537">📝 CodeIgniter System Requirements</h1>
<h2 data-start="539" data-end="559">🔎 Introduction</h2>
<p data-start="560" data-end="763">CodeIgniter is a <strong data-start="577" data-end="606">lightweight PHP framework</strong> that runs on most web servers with minimal configuration. However, depending on the version (CodeIgniter 3 or 4), the system requirements differ slightly.</p>
<p data-start="765" data-end="850">Let&rsquo;s go through the <strong data-start="786" data-end="810">minimum requirements</strong> for running CodeIgniter applications.</p>
<hr data-start="852" data-end="855" />
<h2 data-start="857" data-end="884">⚙️ 1. PHP Requirements</h2>
<h3 data-start="886" data-end="925">🔹 CodeIgniter 4 (Latest Version)</h3>
<ul data-start="926" data-end="1344">
<li data-start="926" data-end="999">
<p data-start="928" data-end="999"><strong data-start="928" data-end="943">PHP Version</strong>: <code data-start="945" data-end="954">PHP 7.4</code> or higher (recommended: PHP 8.1 or above).</p>
</li>
<li data-start="1000" data-end="1344">
<p data-start="1002" data-end="1028"><strong data-start="1002" data-end="1025">Required Extensions</strong>:</p>
<ul data-start="1031" data-end="1344">
<li data-start="1031" data-end="1086">
<p data-start="1033" data-end="1086"><code data-start="1033" data-end="1039">intl</code> &rarr; For internationalization and localization.</p>
</li>
<li data-start="1089" data-end="1136">
<p data-start="1091" data-end="1136"><code data-start="1091" data-end="1101">mbstring</code> &rarr; For multibyte string handling.</p>
</li>
<li data-start="1139" data-end="1175">
<p data-start="1141" data-end="1175"><code data-start="1141" data-end="1147">json</code> &rarr; For JSON data handling.</p>
</li>
<li data-start="1178" data-end="1219">
<p data-start="1180" data-end="1219"><code data-start="1180" data-end="1189">mysqlnd</code> &rarr; For database interaction.</p>
</li>
<li data-start="1222" data-end="1255">
<p data-start="1224" data-end="1255"><code data-start="1224" data-end="1233">php-xml</code> &rarr; For XML handling.</p>
</li>
<li data-start="1258" data-end="1297">
<p data-start="1260" data-end="1297"><code data-start="1260" data-end="1266">curl</code> &rarr; For sending HTTP requests.</p>
</li>
<li data-start="1300" data-end="1344">
<p data-start="1302" data-end="1344"><code data-start="1302" data-end="1311">openssl</code> &rarr; For encryption and security.</p>
</li>
</ul>
</li>
</ul>
<h3 data-start="1346" data-end="1385">🔹 CodeIgniter 3 (Legacy Version)</h3>
<ul data-start="1386" data-end="1631">
<li data-start="1386" data-end="1445">
<p data-start="1388" data-end="1445"><strong data-start="1388" data-end="1403">PHP Version</strong>: Minimum <code data-start="1413" data-end="1422">PHP 5.6</code>, works with PHP 7.x.</p>
</li>
<li data-start="1446" data-end="1526">
<p data-start="1448" data-end="1526"><strong data-start="1448" data-end="1463">Recommended</strong>: Use <code data-start="1469" data-end="1478">PHP 7.2</code> or above for better performance and security.</p>
</li>
<li data-start="1527" data-end="1631">
<p data-start="1529" data-end="1631">Fewer extensions required compared to CI4 (but <code data-start="1576" data-end="1586">mbstring</code>, <code data-start="1588" data-end="1596">mysqli</code>, and <code data-start="1602" data-end="1611">openssl</code> are recommended).</p>
</li>
</ul>
<hr data-start="1633" data-end="1636" />
<h2 data-start="1638" data-end="1671">🗄️ 2. Database Requirements</h2>
<p data-start="1672" data-end="1721">CodeIgniter supports multiple database systems:</p>
<ul data-start="1723" data-end="1847">
<li data-start="1723" data-end="1776">
<p data-start="1725" data-end="1776"><strong data-start="1725" data-end="1751">MySQL (5.1+) / MariaDB</strong> ✅ (most commonly used)</p>
</li>
<li data-start="1777" data-end="1791">
<p data-start="1779" data-end="1791">PostgreSQL</p>
</li>
<li data-start="1792" data-end="1803">
<p data-start="1794" data-end="1803">SQLite3</p>
</li>
<li data-start="1804" data-end="1828">
<p data-start="1806" data-end="1828">Microsoft SQL Server</p>
</li>
<li data-start="1829" data-end="1839">
<p data-start="1831" data-end="1839">Oracle</p>
</li>
<li data-start="1840" data-end="1847">
<p data-start="1842" data-end="1847">DB2</p>
</li>
</ul>
<p data-start="1849" data-end="1955">👉 Make sure you enable the respective <strong data-start="1888" data-end="1913">PHP driver extensions</strong> (e.g., <code data-start="1921" data-end="1929">mysqli</code>, <code data-start="1931" data-end="1942">pdo_mysql</code>, <code data-start="1944" data-end="1951">pgsql</code>).</p>
<hr data-start="1957" data-end="1960" />
<h2 data-start="1962" data-end="1996">🌐 3. Web Server Requirements</h2>
<ul data-start="1997" data-end="2207">
<li data-start="1997" data-end="2046">
<p data-start="1999" data-end="2046"><strong data-start="1999" data-end="2016">Apache (2.4+)</strong> or <strong data-start="2020" data-end="2029">Nginx</strong> (recommended).</p>
</li>
<li data-start="2047" data-end="2115">
<p data-start="2049" data-end="2115">Works with <strong data-start="2060" data-end="2090">XAMPP, WAMP, LAMP, or MAMP</strong> for local development.</p>
</li>
<li data-start="2116" data-end="2207">
<p data-start="2118" data-end="2207">Ensure <strong data-start="2125" data-end="2140">mod_rewrite</strong> is enabled in Apache if you want clean URLs without <code data-start="2193" data-end="2204">index.php</code>.</p>
</li>
</ul>
<hr data-start="2209" data-end="2212" />
<h2 data-start="2214" data-end="2250">🖥️ 4. Operating System Support</h2>
<ul data-start="2251" data-end="2387">
<li data-start="2251" data-end="2264">
<p data-start="2253" data-end="2264">✅ Windows</p>
</li>
<li data-start="2265" data-end="2307">
<p data-start="2267" data-end="2307">✅ Linux (Ubuntu, CentOS, Fedora, etc.)</p>
</li>
<li data-start="2308" data-end="2319">
<p data-start="2310" data-end="2319">✅ macOS</p>
</li>
<li data-start="2320" data-end="2387">
<p data-start="2322" data-end="2387">Runs on any OS where PHP and supported databases are installed.</p>
</li>
</ul>
<hr data-start="2389" data-end="2392" />
<h2 data-start="2394" data-end="2432">🛠️ 5. Additional Recommendations</h2>
<ul data-start="2433" data-end="2632">
<li data-start="2433" data-end="2507">
<p data-start="2435" data-end="2507"><strong data-start="2435" data-end="2447">Composer</strong> &rarr; Required for CodeIgniter 4 installation &amp; dependencies.</p>
</li>
<li data-start="2508" data-end="2590">
<p data-start="2510" data-end="2590"><strong data-start="2510" data-end="2527">Node.js &amp; npm</strong> &rarr; Optional, if using frontend build tools (CSS/JS bundling).</p>
</li>
<li data-start="2591" data-end="2632">
<p data-start="2593" data-end="2632"><strong data-start="2593" data-end="2602">HTTPS</strong> &rarr; Recommended for security.</p>
</li>
</ul>
<hr data-start="2634" data-end="2637" />
<h2 data-start="2639" data-end="2691">✅ Quick Checklist Before Installing CodeIgniter</h2>
<ul class="contains-task-list" data-start="2693" data-end="2953">
<li class="task-list-item" data-start="2693" data-end="2729">
<p data-start="2699" data-end="2729"><input disabled="disabled" type="checkbox" /> PHP 7.4+ (preferably PHP 8+)</p>
</li>
<li class="task-list-item" data-start="2730" data-end="2814">
<p data-start="2736" data-end="2814"><input disabled="disabled" type="checkbox" /> Enabled extensions: <code data-start="2756" data-end="2762">intl</code>, <code data-start="2764" data-end="2774">mbstring</code>, <code data-start="2776" data-end="2782">json</code>, <code data-start="2784" data-end="2793">mysqlnd</code>, <code data-start="2795" data-end="2801">curl</code>, <code data-start="2803" data-end="2812">openssl</code></p>
</li>
<li class="task-list-item" data-start="2815" data-end="2870">
<p data-start="2821" data-end="2870"><input disabled="disabled" type="checkbox" /> Database: MySQL/MariaDB (or other supported DB)</p>
</li>
<li class="task-list-item" data-start="2871" data-end="2906">
<p data-start="2877" data-end="2906"><input disabled="disabled" type="checkbox" /> Web server: Apache or Nginx</p>
</li>
<li class="task-list-item" data-start="2907" data-end="2953">
<p data-start="2913" data-end="2953"><input disabled="disabled" type="checkbox" /> Composer installed (for CodeIgniter 4)</p>
</li>
</ul>
<hr data-start="2955" data-end="2958" />
<h2 data-start="2960" data-end="2978">🎯 Conclusion</h2>
<p data-start="2979" data-end="3133">CodeIgniter requires only a <strong data-start="3007" data-end="3032">basic LAMP/WAMP stack</strong> with PHP and MySQL/MariaDB, making it one of the most <strong data-start="3087" data-end="3130">lightweight and flexible PHP frameworks</strong>.</p>
<p data-start="3135" data-end="3268">By ensuring your environment meets these requirements, you&rsquo;ll have a smooth experience installing and running CodeIgniter projects.</p>

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