International Slug Transliterator – Remove Diacritics for URLs

A URL slug is the human-readable portion of a URL that identifies a specific page, typically coming after the domain. For example, in example.com/blog/my-article-title, the slug is "my-article-title". Well-crafted slugs are critical for SEO because search engines use them to understand page content, and users are more likely to click on clean, descriptive URLs. A good slug should be concise, readable, and free of special characters or diacritics.

Diacritics (also called accent marks) are glyphs added to letters to alter pronunciation or meaning — such as é, ñ, ü, ç, and ø. While they are essential in written language, they can cause compatibility issues in URLs. Non-ASCII characters in URLs are percent-encoded (e.g., %C3%A9 for é), making them unreadable and potentially breaking links across different systems, email clients, and social media platforms. Removing diacritics ensures your URLs are universally accessible and visually clean.

Our transliterator supports 30+ languages covering major diacritic systems worldwide:

• Romance: French, Spanish, Portuguese, Italian, Romanian, Catalan
• Germanic: German, Swedish, Danish, Norwegian, Icelandic, Dutch
• Slavic: Polish, Czech, Slovak, Croatian, Slovenian, Serbian (Latin)
• Baltic: Latvian, Lithuanian, Estonian
• Others: Turkish, Hungarian, Finnish, Vietnamese, Albanian, Maltese, Esperanto

The mapping table includes 200+ character conversions covering Latin-1 Supplement, Latin Extended-A, and Latin Extended-B Unicode blocks.

Multi-character ligatures and special letters are intelligently expanded:

• ß (German eszett) → ss
• æ (ash ligature) → ae
• œ (ethel ligature) → oe
• þ (Icelandic thorn) → th
• ð (Icelandic eth) → d
• ø (Nordic o-slash) → o
• ł (Polish l-stroke) → l
• đ (Croatian d-stroke) → d

These expansions follow widely-accepted URL conventions to maintain readability while ensuring compatibility.

Hyphens are strongly recommended for SEO. Google explicitly treats hyphens as word separators, meaning my-article-title is read as three separate words: "my", "article", and "title". Underscores, however, are treated as joiners — my_article_title is interpreted as a single compound token. This makes hyphens far more effective for keyword matching. Our tool defaults to hyphens, but offers underscore as an option for systems that require it (e.g., certain CMS platforms or legacy APIs).

For optimal SEO, keep slugs between 30 and 60 characters. Shorter slugs (under 30 chars) may lack descriptive keywords, while excessively long slugs (over 60 chars) can be truncated in search results and are harder for users to read. Our tool includes a length indicator that shows green for ideal lengths, yellow for longer slugs, and blue for very short ones — helping you craft the perfect URL every time.

By default, non-ASCII characters (including CJK and Cyrillic) that don't have a Latin diacritic mapping are removed from the slug. This ensures maximum compatibility across browsers, servers, and CDNs. However, modern browsers can display Unicode in URLs (using percent-encoding behind the scenes). If you need to preserve CJK characters in your slug, consider combining this tool with a romanization service (such as Pinyin for Chinese or Romaji for Japanese) before generating the slug. For Cyrillic, transliteration to Latin is recommended (e.g., Москва → moskva).

Yes. The generated slug contains only ASCII alphanumeric characters (a-z, 0-9) and your chosen separator (hyphen or underscore). This restricted character set is universally accepted across:

• Web servers: Apache, Nginx, IIS, LiteSpeed
• Operating systems: Windows, Linux, macOS file systems
• DNS and CDN: Cloudflare, AWS CloudFront, Akamai
• Databases: MySQL, PostgreSQL, MongoDB URL fields
• Email clients: Gmail, Outlook, Apple Mail (no broken encoding)

Pure ASCII slugs eliminate percent-encoding issues and ensure your links work everywhere, every time.

This web tool is designed for interactive, one-off slug generation. For bulk processing or API integration, consider implementing the diacritic mapping table shown in this tool within your backend code. The core algorithm is straightforward: apply a character mapping (200+ entries), replace whitespace with separators, strip non-alphanumeric characters, and normalize. Popular server-side libraries like slugify (Node.js), python-slugify (Python), Stringex (Ruby), and Slug (PHP/Laravel) offer similar functionality with API access.

Characters that are neither diacritic letters nor alphanumeric are stripped during slug generation. This includes:

• Punctuation: ! ? . , ; : " ' ( ) [ ] { }
• Symbols: € $ £ ¥ % @ # & * + = ~ `
• Emoji: 😊 🚀 ❤️ (removed entirely)
• Non-Latin scripts without mapping: Arabic, Hebrew, Thai, Devanagari, etc.

This behavior is intentional — a clean URL slug should only contain descriptive words. If you notice a specific diacritic character that isn't being converted properly, it may be a rare Unicode character not in our mapping table. Please let us know and we can expand the mapping!

Follow these proven SEO guidelines for optimal URL slugs:

1. Keep it concise: 3-5 words, ideally 30-60 characters
2. Use target keywords: Include your primary keyword naturally
3. Remove stop words: Omit "a", "the", "and", "of", "in" where possible
4. Use hyphens: Not underscores, for word separation
5. All lowercase: Avoid mixed case (some servers are case-sensitive)
6. No dates: Avoid year/month in slugs unless essential for context
7. Make it readable: A human should understand the page topic from the URL alone
8. Unique slugs only: Never reuse the same slug for different content

Unlike basic slug generators that only handle a handful of Western European accents, our tool features:

• 200+ diacritic mappings covering Central & Eastern European, Nordic, Baltic, and Turkish characters
• Intelligent multi-character expansions (ß→ss, æ→ae, œ→oe, þ→th)
• Real-time diacritic detection showing exactly which characters are being converted
• Length quality indicator for SEO-optimized slug lengths
• URL preview so you can visualize the final link
• Flexible options for separator choice, number handling, and trimming behavior

Most free online tools stop at basic French/German accents. We go much further to serve a truly global audience.