PrestaShop Performance Optimization

PrestaShop Performance Optimization

PrestaShop 8.x on standard configuration gives TTFB 1.5–4 seconds on catalog with 2000+ products. Reasons: Smarty template compilation without cache, ORM with excessive JOIN queries, built-in file-based cache. Optimization gives TTFB 200–500ms with correct stack.

PrestaShop Built-in Cache

Admin > Advanced Parameters > Performance — main optimization panel.

Smarty:

• Template compilation: Never recompile template files (not on dev)
• Cache: Yes
• Multi-front optimizations: Yes
• Clear cache: Never clear cache files

CCC (Combine, Compress, Cache):

• Smart cache for stylesheets: Yes
• Smart cache for JavaScript: Yes
• Apache optimization: Yes (generates .htaccess rules)
• Minify HTML: Yes

Media servers — specify CDN domain for static files if used.

Memcache/Redis as Cache Backend

By default PrestaShop caches to files. Switch to Memcache or Redis through Admin > Advanced Parameters > Performance > Caching:

• Caching system: Memcache or Redis
• Add server: 127.0.0.1:6379

For Redis additionally in config/config.inc.php (if version doesn't support Redis via UI):

define('_PS_CACHE_ENABLED_', '1');
define('_PS_CACHING_SYSTEM_', 'CacheRedis');

CacheRedis class in PrestaShop 8 works via Predis. If using phpredis extension — 15–20% faster.

PHP OPcache

opcache.enable=1
opcache.memory_consumption=256
opcache.max_accelerated_files=20000
opcache.validate_timestamps=0    ; production
opcache.revalidate_freq=0
opcache.interned_strings_buffer=32
opcache.fast_shutdown=1

PrestaShop has large codebase — max_accelerated_files=20000 is necessary, standard 10000 is not enough.

MySQL: Indexes and Slow Log

-- Common PrestaShop queries without optimal index
ALTER TABLE ps_product_lang
  ADD INDEX idx_id_lang (id_lang, id_product);

ALTER TABLE ps_category_product
  ADD INDEX idx_id_category_pos (id_category, position);

ALTER TABLE ps_search_word
  ADD INDEX idx_word (word(50));

Slow query log:

[mysqld]
slow_query_log = 1
slow_query_log_file = /var/log/mysql/prestashop-slow.log
long_query_time = 1
log_queries_not_using_indexes = 1

Typical culprit in slow log — getProducts() query sorted by sales without index on ps_product_sale.

Modules and Their Performance Impact

Each active PrestaShop module adds hooks to page lifecycle. Diagnostics:

// config/defines.inc.php (temporarily)
define('_PS_DEBUG_PROFILING_', true);

After enabling, Debugger bar appears at bottom of page in browser with execution time for each hook.

Problematic module categories:

• SEO modules — often make 3–10 additional requests per page
• Live chat modules — load external scripts synchronously
• Review modules — COUNT queries without cache for each product in listing

Nginx Configuration

# Static files
location ~* \.(jpg|jpeg|png|webp|gif|ico|svg|woff2|css|js)$ {
    expires 1y;
    add_header Cache-Control "public, immutable";
    access_log off;
    try_files $uri =404;
}

# Gzip
gzip on;
gzip_types text/plain text/css application/json application/javascript image/svg+xml;
gzip_comp_level 5;
gzip_min_length 512;
gzip_vary on;

# Forbid direct access to PrestaShop classes
location ~* \.(log|tpl|twig|sass|yml|lock)$ {
    deny all;
}

WebP and Images

PrestaShop 1.7.7+ supports WebP via Admin > Design > Image settings. Enable WebP formats — image sizes reduced by 25–40%. On listing page with 24 products, saves 500–800 KB.

Additionally — regenerate thumbnails with new sizes:

php bin/console prestashop:generate:thumbnails --type=all

Work Timeline

Setup built-in cache, OPcache, PHP-FPM, Redis, nginx: 1–2 days. Module audit and disabling slow ones: 1 day. Enable WebP, regenerate thumbnails, MySQL indexes: 0.5–1 day.