Text cleaner & slug generator

Why clean URLs matter

A good URL tells people and search engines what the page is about before they open it. The basics are simple: lowercase letters, words separated by hyphens, short, readable and free of tracking parameters or session IDs. Google's documentation recommends hyphens over underscores because its systems can treat hyphens as word separators but not underscores. A slug such as clean-url-slugs reads as three words, while clean_url_slugs may be read as one long string. Use the slug generator for a whole content plan at once, then check how the address will look in results with the SERP simulator.

Keep slugs short, drop filler words, and avoid dates or numbers that will go stale. Once a page is indexed, treat its slug as permanent: if you must change it, set up a 301 redirect from the old address to the new one.

Why multilingual sites should avoid diacritics in URLs

Accented characters are allowed in URLs, but they travel in percent-encoded form. The Romanian word “școală” (school) becomes %C8%99coal%C4%83 as soon as someone copies the link into an email or a report. Different tools may show the encoded or the decoded form, which makes analytics, redirects and sitemaps harder to keep consistent and can produce accidental duplicates. On a site with several language versions, plain ASCII slugs such as scoala-de-vara avoid all of that. Keep the accents in the title and body, where they belong, and keep the slug simple. If you publish in several languages, the hreflang guide explains how to connect the versions.

Invisible characters that break copy-paste and your CMS

Text pasted from PDFs, messaging apps, slide decks and AI tools often carries characters you cannot see: zero-width spaces, byte order marks, soft hyphens and left-to-right marks. They cause real problems. A form validator rejects an email address that looks fine. A product code fails to match in a spreadsheet. A word is split in site search, or a heading shows a stray box in some fonts. In a URL or a redirect rule, an invisible character quietly produces a different address. The cleaner lists every hidden character with its code point and its line and column, so you can find out where it came from, and removes it with one switch.

Title Case or sentence case?

Both are legitimate. Title Case suits headlines in American publishing and many brands. Sentence case, where only the first word and proper nouns are capitalized, usually reads as more conversational and is common in interface text and many style guides. The important part is consistency: pick one style for headings and title tags, and apply it everywhere. The Case & counts tab implements a simplified AP-style Title Case and a sentence case that preserves acronyms. For guidance on writing titles that earn clicks, see how to write title tags and meta descriptions.

Typographic quotes and dashes

Word processors turn straight quotes into curly ones automatically, so text moves between editors with a mix of both. That is harmless in prose but troublesome in code, JSON, HTML attributes and search queries, where only the straight characters work. In the other direction, curly quotes and proper dashes look more polished in published articles. Choose the direction that fits the destination: straight for code and data, curly for finished copy. The same goes for en and em dashes and the single ellipsis character.

Common mistakes

Typical problems are pasting from a word processor straight into a CMS, leaving double spaces after periods, mixing quote styles in one article, using underscores in slugs, shipping slugs of more than 60 characters, and changing live URLs without redirects. Clean the text first, then optimize the page. If you want help with titles, headings and on-page structure across a whole site, take a look at our on-page SEO service. Image file names deserve the same care as page slugs, as covered in image SEO with WebP and alt text.