★ LaunchRadar

European alternatives to Thesaurus.com

Thesaurus.com dominates US English synonym lookup but holds 0% market share in EU offices that demand data residency. Most exodus happens at the compliance boundary: GDPR, data sovereignty, or open-source requirements.

Thesaurus.com offers breadth — 950,000+ synonyms across 4.5 million monthly users. Its free tier covers basic lookup; premium adds nothing material for most writers. The problem is location: US-hosted, US-owned (Dotdash Meredith), zero transparency on data processing. Any EU entity auditing data flows hits a wall. German shops writing in German find a tool optimized for English idiom, not regional tone. Swedish teams get English-first UX, Swedish-second (if at all).

The secondary exodus is ideological. Open-source advocates lose: Thesaurus.com is not self-hostable, not open, not auditable. Libraries integrating synonym lookup into workflows can't build on it. Teams with offline requirements or air-gapped networks find Thesaurus.com inaccessible. And language communities see thin coverage: Thesaurus.com's strength is English; non-English synonyms are shallow or borrowed from other vendors.

Where each alternative is built, owned and hosted

Read the billing unit, deployment scope and supporting evidence. Missing documentation is not a negative finding. On small screens, scroll the table sideways.

Where each alternative is built, owned and hosted
ProductPricing and billing unitData and deployment scopeSelf-hosting / Source code
Cambridge Dictionary & ThesaurusView evidence →Catalog information: FreemiumNot documented hereNot documented here

Self-hosting

Not documented here

Source code

Not documented here
Collins Dictionary ThesaurusView evidence →Catalog information: FreemiumNot documented hereNot documented here

Self-hosting

Not documented here

Source code

Not documented here
Duden SynonymeView evidence →Catalog information: FreemiumNot documented hereNot documented here

Self-hosting

Not documented here

Source code

Not documented here
LarousseView evidence →Catalog information: FreeNot documented hereNot documented here

Self-hosting

Not documented here

Source code

Not documented here
Larousse Dictionnaire des SynonymesView evidence →Catalog information: FreeNot documented hereNot documented here

Self-hosting

Not documented here

Source code

Not documented here
Le Robert Online Dictionary & ThesaurusView evidence →Catalog information: FreemiumNot documented hereNot documented here

Self-hosting

Not documented here

Source code

Not documented here
Lingea Synonym Dictionary (Czech)View evidence →Catalog information: PaidNot documented hereNot documented here

Self-hosting

Not documented here

Source code

Not documented here
OpenThesaurusView evidence →Catalog information: FreeNot documented hereNot documented here

Self-hosting

Not documented here

Source code

Not documented here
Ordsynonymerby the founderView evidence →Catalog information: FreeNot documented hereNot documented here

Self-hosting

Not documented here

Source code

Not documented here
ReversoView evidence →Catalog information: FreemiumNot documented hereNot documented here

Self-hosting

Not documented here

Source code

Not documented here
Reverso SynonymsView evidence →Catalog information: FreemiumNot documented hereNot documented here

Self-hosting

Not documented here

Source code

Not documented here
Synoniemen.netView evidence →Catalog information: FreeNot documented hereNot documented here

Self-hosting

Not documented here

Source code

Not documented here
Synonymo.frView evidence →Catalog information: FreeNot documented hereNot documented here

Self-hosting

Not documented here

Source code

Not documented here
Tyda.seView evidence →Catalog information: FreeNot documented hereNot documented here

Self-hosting

Not documented here

Source code

Not documented here
WoxikonView evidence →Catalog information: FreeNot documented hereNot documented here

Self-hosting

Not documented here

Source code

Not documented here
Cambridge Dictionary & Thesaurus screenshot

Cambridge Dictionary & Thesaurus

gb

The authoritative free English dictionary and thesaurus from Cambridge University Press with 170,000 words and integrated synonyms.

  • Catalog information
FreemiumVisit →
Collins Dictionary Thesaurus screenshot

Collins Dictionary Thesaurus

gb

Comprehensive English thesaurus with 500,000+ synonyms and antonyms from HarperCollins

  • Catalog information
FreemiumVisit →
Duden Synonyme screenshot

Duden Synonyme

de

Germany's authoritative online synonym and thesaurus reference for expressing yourself more effectively

  • Catalog information
FreemiumVisit →
Larousse screenshot

Larousse

fr

French-owned multilingual dictionary, thesaurus, and language reference platform offering free access to comprehensive word definitions, synonyms, and translations.

  • Catalog information
FreeVisit →
Larousse Dictionnaire des Synonymes screenshot

Larousse Dictionnaire des Synonymes

fr

A comprehensive free online French synonym and antonym dictionary with 160,000+ entries and contextual usage guidance.

  • Catalog information
FreeVisit →
Le Robert Online Dictionary & Thesaurus screenshot

Le Robert Online Dictionary & Thesaurus

fr

Authoritative French dictionary and thesaurus with 145,000 definitions and 220,000+ synonyms.

  • Catalog information
FreemiumVisit →
Lingea Synonym Dictionary (Czech) screenshot

Lingea Synonym Dictionary (Czech)

cz

Comprehensive Czech synonym and antonym dictionary from 30-year language technology publisher.

  • Catalog information
PaidVisit →
OpenThesaurus screenshot

OpenThesaurus

de

A libre, self-hostable German thesaurus for synonyms and word associations.

  • Catalog information
FreeVisit →
Ordsynonymer screenshot

Ordsynonymer

se

Swedish synonym dictionary.

  • Catalog information
Free· By the LaunchRadar founderVisit →
Reverso screenshot

Reverso

FR

AI-powered translation, dictionary, and thesaurus with context-driven learning for 80 million users globally.

  • Catalog information
FreemiumVisit →
Reverso Synonyms screenshot

Reverso Synonyms

fr

Context-aware synonym and thesaurus service for 15+ languages.

  • Catalog information
FreemiumVisit →
Synoniemen.net screenshot

Synoniemen.net

nl

Free Dutch synonyms and multi-language translation dictionary with privacy-first design.

  • Catalog information
FreeVisit →
Synonymo.fr screenshot

Synonymo.fr

fr

Simple, fast, and free French synonym dictionary.

  • Catalog information
FreeVisit →
Tyda.se screenshot

Tyda.se

se

Sweden's largest free dictionary for synonyms, translations, and word discovery across Nordic and European languages.

  • Catalog information
FreeVisit →
Woxikon screenshot

Woxikon

de

Free multilingual synonym dictionary and thesaurus for 20+ languages

  • Catalog information
FreeVisit →

Our honest take

European buyers split by use-case. Institutions needing standardized, open taxonomy: EuroVoc (7,000 concepts in 24+ EU languages, SPARQL endpoint, downloadable EUPL open license). German writers: OpenThesaurus (AGPL + CC-BY-SA, 60 req/min API, built into LibreOffice) or Duden Synonyme (context-aware grouping by meaning, style levels). French professionals: Larousse (160,000 synonyms, free web access, Larousse ecosystem integration) or Reverso Synonyms (70M monthly users, 15+ languages, real example sentences). Dutch teams: Synoniemen.net (14,112 headwords, privacy-respecting, no Google Analytics). Swedish users: Synonymer.se (2M monthly users, word games, 70K newsletter) or Tyda.se (1.5M+ entries, free, Scandinavian focus).

Ordsynonymer fits a narrower slot: Swedish/EU-focused SMEs wanting EU-hosted thesaurus, zero vendor risk, no compliance overhead. It loses on breadth (narrower corpus than Thesaurus.com), non-Swedish languages (single-language focus), and ecosystem integration (not built into office suites). It wins on data location (EU-hosted), zero pricing friction (free), and honest limits (you know what you get).

Related European alternatives

Browse related categories

What we compare

  • Where the data is stored
  • Who owns the company
  • Documented data and deployment scope
  • Self-hosting option
  • Open source
  • Pricing model
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