Locale Format Reference for International SEO

Load this reference when validating content parity or generating localized content. Mismatched formats (e.g., US date format on a German page) signal poor localization and reduce user trust.

Original concept: Chris Muller (Pro Hub Challenge)

Number Formats

Locale	Thousands	Decimal	Example
en-US	,	.	1,234.56
en-GB	,	.	1,234.56
de-DE	.	,	1.234,56
de-AT	.	,	1.234,56
de-CH	'	.	1'234.56
fr-FR	(space)	,	1 234,56
fr-CA	(space)	,	1 234,56
es-ES	.	,	1.234,56
es-MX	,	.	1,234.56
ja-JP	,	.	1,234
pt-BR	.	,	1.234,56
it-IT	.	,	1.234,56
nl-NL	.	,	1.234,56
ko-KR	,	.	1,234
zh-CN	,	.	1,234.56

Date Formats

Locale	Format	Example
en-US	MM/DD/YYYY	04/14/2026
en-GB	DD/MM/YYYY	14/04/2026
de-DE	DD.MM.YYYY	14.04.2026
fr-FR	DD/MM/YYYY	14/04/2026
es-ES	DD/MM/YYYY	14/04/2026
ja-JP	YYYY/MM/DD or YYYY年MM月DD日	2026/04/14
pt-BR	DD/MM/YYYY	14/04/2026
ko-KR	YYYY.MM.DD	2026.04.14
zh-CN	YYYY年MM月DD日	2026年04月14日

Currency Formats

Locale	Symbol	Placement	Example
en-US	$	Before	$1,234.56
en-GB	£	Before	£1,234.56
de-DE	€	After (space)	1.234,56 €
fr-FR	€	After (space)	1 234,56 €
es-ES	€	After (space)	1.234,56 €
ja-JP	¥	Before	¥1,234
pt-BR	R$	Before	R$ 1.234,56
ko-KR	₩	Before	₩1,234
zh-CN	¥	Before	¥1,234.56
de-CH	CHF	Before	CHF 1'234.56

Address Formats

Region	Order	Example
US/CA	Street, City, State ZIP	123 Main St, Austin, TX 78701
UK	Street, City, Postcode	10 Downing St, London, SW1A 2AA
DE/AT	Street Nr, PLZ City	Hauptstr. 1, 10115 Berlin
FR	Street, Code Postal City	1 Rue de Rivoli, 75001 Paris
JP	Postal City District Street	〒100-0001 東京都千代田区千代田1-1

Phone Formats

Region	Format	Example
US	+1 (XXX) XXX-XXXX	+1 (512) 555-0123
UK	+44 XXXX XXXXXX	+44 2071 234567
DE	+49 XXX XXXXXXX	+49 30 12345678
FR	+33 X XX XX XX XX	+33 1 23 45 67 89
JP	+81 X-XXXX-XXXX	+81 3-1234-5678

Text Expansion Ratios (vs English)

Language	Expansion	Impact
German	+25-35%	Longer headlines, buttons, navigation labels
French	+15-25%	Moderate expansion
Spanish	+15-25%	Moderate expansion
Italian	+15-25%	Moderate expansion
Portuguese	+15-25%	Moderate expansion
Dutch	+10-20%	Slight expansion
Japanese	-10-25%	Contraction (more compact)
Korean	-10-20%	Contraction
Chinese	-20-30%	Significant contraction

Validation Rules

When checking locale format consistency: 1. Scan for number patterns on the page (prices, statistics, measurements) 2. Compare against the expected format for the page's declared language 3. Flag US-format numbers on non-US pages (e.g., "$1,234.56" on a de-DE page) 4. Check date formats in blog posts, copyright notices, update timestamps 5. Verify currency symbols match the target market 6. Check that phone numbers use international format with correct country code