The 200-byte trap: why WordPress core updates break Arabic URLs

You update WordPress on a quiet afternoon — a routine release, the kind you've installed a hundred times. The dashboard says everything went fine. Then the 404s start: not a handful, but every long-headlined article in your archive, all at once, all in Arabic. Nothing in the update log mentions it. No plugin changed. And the cruel part: the data that made those URLs work is already gone — shaved off inside a database-upgrade routine that ran for a few milliseconds and reported success. This isn't a freak accident or a broken plugin. It's three separate assumptions baked into WordPress core, each hard-coding the same number — 200 — and Arabic sites are almost uniquely exposed to all three. We hit this running WordPress for Arabic newsrooms, the same high-traffic publishing we've written about surviving breaking-news spikes . We traced it to the exact lines in core and built a fix that survives every future update. Here's the whole story. Why Arabic URLs hit a wall English never does WordPress stores a post's slug in the post_name column of wp_posts , and a category or tag slug in the slug column of wp_terms . Both are VARCHAR(200) by default — room for 200 characters, which for an English headline is generous. "Everything you need to know about our new pricing" is barely fifty. You'd have to write a paragraph to run out. Arabic is a different arithmetic, because of what WordPress actually stores in that column. It doesn't keep the raw Arabic text — it stores the percent-encoded form, the same %XX sequence that travels in the URL. Take a single word: الذكاء → %d8%a7%d9%84%d8%b0%d9%83%d8%a7%d8%a1 Every Arabic letter is two bytes in UTF-8, and every byte becomes a three-character %XX token. So one Arabic character costs about six characters of column space. Do the division: VARCHAR(200) holds roughly 33 Arabic characters. A normal news headline — "القبض على المتهمين في قضية الاحتيال الإلكتروني" — blows past that before it's halfway done. So Arabic publishers learn early