The search_domain_filter feature allows you to limit search results to specific domains/URLs or exclude certain domains/URLs from search results. This supports both broad domain-level filtering and granular URL-level filtering for precise content control.
You can add a maximum of 10 domains or URLs to the search_domain_filter list. The filter works in either allowlist mode (include only) or denylist mode (exclude), but not both simultaneously.
Before adding URLs to your allowlist, test that they are accessible via the API by making a sample request. URLs that are blocked, require authentication, or have access restrictions may not return search results, which can significantly impact response quality when using allowlist mode.

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Overview

The search_domain_filter parameter allows you to control which websites are included in or excluded from the search results used by the Sonar models. This feature is particularly useful when you want to:
  • Restrict search results to trusted sources
  • Filter out specific domains from search results
  • Focus research on particular websites
Enabling domain filtering can be done by adding a search_domain_filter field in the request: 
"search_domain_filter": [
  "<domain1>",
  "<domain2>",
  ...
]
Each entry in the list can be a domain name or a specific URL. The filter operates in two modes:
  • Allowlist mode: Include only the specified domains/URLs (no - prefix)
  • Denylist mode: Exclude the specified domains/URLs (use - prefix)

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Filtering Capabilities

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Domain-Level Filtering

Filter entire domains for broad control: 
// Allowlist: Only search these domains
"search_domain_filter": ["wikipedia.org", "github.com", "stackoverflow.com"]

// Denylist: Exclude these domains  
"search_domain_filter": ["-reddit.com", "-pinterest.com", "-quora.com"]

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URL-Level Filtering

Target specific pages or sections for granular control: 
// Allowlist: Only search these specific URLs
"search_domain_filter": [
  "https://en.wikipedia.org/wiki/Chess",
  "https://stackoverflow.com/questions/tagged/python",
  "https://docs.python.org/3/tutorial/"
]

// Denylist: Exclude these specific URLs
"search_domain_filter": [
  "-https://en.wikipedia.org/wiki/FIDE_rankings",
  "-https://reddit.com/r/politics"
]
This granular approach allows you to:
  • Include or exclude specific Wikipedia articles while keeping/removing the rest
  • Target particular sections of large sites like Stack Overflow or Reddit
  • Filter specific documentation pages or subdirectories

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Examples

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1. Allowlist Specific Domains

This example shows how to limit search results to only include content from specific domains. Request 
curl --request POST \
  --url https://api.perplexity.ai/chat/completions \
  --header 'Authorization: Bearer YOUR_API_KEY' \
  --header 'Content-Type: application/json' \
  --data '{
    "model": "sonar-reasoning-pro",
    "messages": [
      {"role": "system", "content": "You are a helpful assistant."},
      {"role": "user", "content": "Tell me about the James Webb Space Telescope discoveries."}
    ],
    "search_domain_filter": [
      "nasa.gov",
      "wikipedia.org",
      "space.com"
    ]
  }'
Best Practice: Use simple domain names (e.g., wikipedia.org) without additional elements like https:// or www. prefixes.

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2. Denylist Specific Domains

This example shows how to exclude specific domains from search results by prefixing the domain name with a minus sign (-). Request 
curl --request POST \
  --url https://api.perplexity.ai/chat/completions \
  --header 'Authorization: Bearer YOUR_API_KEY' \
  --header 'Content-Type: application/json' \
  --data '{
    "model": "sonar-deep-research",
    "messages": [
      {"role": "system", "content": "You are a helpful assistant."},
      {"role": "user", "content": "What are the latest advancements in renewable energy?"}
    ],
    "search_domain_filter": [
      "-pinterest.com",
      "-reddit.com",
      "-quora.com"
    ]
  }'
Best Practice: Use simple domain names with a minus prefix (e.g., -pinterest.com) to exclude domains from search results.

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3. URL-Level Filtering for Granular Control

This example shows how to exclude specific pages while keeping the rest of the domain accessible. Request 
curl --request POST \
  --url https://api.perplexity.ai/chat/completions \
  --header 'Authorization: Bearer YOUR_API_KEY' \
  --header 'Content-Type: application/json' \
  --data '{
    "model": "sonar-pro",
    "messages": [
      {"role": "system", "content": "You are a helpful assistant."},
      {"role": "user", "content": "Tell me about chess rankings and tournaments."}
    ],
    "search_domain_filter": [
      "-https://en.wikipedia.org/wiki/FIDE_rankings"
    ]
  }'
Result: This will search all websites except the specific FIDE rankings Wikipedia page, while keeping all other Wikipedia content accessible. Alternative - Allowlist specific URLs only: 
"search_domain_filter": [
  "https://en.wikipedia.org/wiki/Chess",
  "https://en.wikipedia.org/wiki/World_Chess_Championship",
  "https://chess.com"
]
This would only search those three specific sources and ignore all other websites.

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Best Practices

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Domain and URL Specification

  • Domain filtering: Use simple domain names (e.g., example.com) without protocol prefixes for broad filtering.
  • URL filtering: Use complete URLs including protocol (e.g., https://en.wikipedia.org/wiki/FIDE_rankings) for specific page targeting.
  • Subdomain behavior: Using a main domain (e.g., nytimes.com) will filter all subdomains as well.
  • Granular control: URL-level filtering allows you to include/exclude specific pages while keeping the rest of the domain.

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Filter Optimization

  • Be specific: Use domains/URLs that are most relevant to your query to get the best results.
  • Choose your mode: Use either allowlist mode (include only) OR denylist mode (exclude), but not both in the same request.
  • Limit filter size: You can add up to 10 domains or URLs. Using fewer, more targeted entries often yields better results.
  • URL precision: Use full URLs (including https://) when targeting specific pages for maximum precision.

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Performance Considerations

  • Adding domain filters may slightly increase response time as the search engine needs to apply additional filtering.
  • Overly restrictive domain filters might result in fewer search results, potentially affecting the quality of the response.