generated: '2026-08-13'
method: searched
source: >-
  https://docs.similarweb.com/api-v5/guides/rest-api-data-version-migration,
  https://docs.similarweb.com/api-v5/getting-started/what-s-new-in-v5,
  https://developers.similarweb.com/changelog.rss
description: >-
  Similarweb is mid-generation: API V5 went live 2026-03-03 and the legacy v1/v3/v4 REST
  endpoints carry a published, dated sunset of 2026-10-06 with a one-to-one migration table
  from every old path to its V5 replacement. That is a real deprecation practice with a
  date attached, which is more than most providers publish. What is missing is a public
  status page — no status.similarweb.com, no statuspage.io tenant, and no uptime/SLA page
  was found on any Similarweb host.

versioning:
  scheme: uri-path
  current: v5
  released: '2026-03-03'
  live_versions: [v1, v2, v3, v4, v5]
  docs: https://docs.similarweb.com/api-v5/getting-started/what-s-new-in-v5
  note: >-
    The version segment is per-endpoint, not per-API, so several generations are callable
    at once. V5 unifies response formats, error handling and request patterns across every
    endpoint, and replaces the V4 split where REST and Batch required separate API keys.

deprecation:
  policy_url: https://docs.similarweb.com/api-v5/guides/rest-api-data-version-migration
  sunset_date: '2026-10-06'
  sunset_header: false
  deprecation_header: false
  mechanism: >-
    Published migration table mapping each legacy REST endpoint to its V5 replacement,
    plus a dated deprecation notice in the guide. Delivery is documentation-only —
    Similarweb does not emit RFC 8594 Sunset or Deprecation response headers, so a running
    client gets no runtime signal that it is calling a sunsetting endpoint.
  examples:
  - {old: 'GET /v1/website/{domain}/traffic-sources/overview-share', new: 'GET /v5/website-analysis/websites/traffic-channels/share?web_source=desktop'}
  - {old: 'GET /v4/website/{domain}/traffic-sources/overview', new: 'GET /v5/website-analysis/websites/traffic-channels/share?web_source=desktop'}
  - {old: 'GET /v4/website/{domain}/traffic-sources/referrals', new: 'GET /v5/website-analysis/websites/traffic-referrals/incoming?web_source=desktop'}
  - {old: 'GET /v4/website/{domain}/traffic-sources/outgoing-referrals', new: 'GET /v5/website-analysis/websites/traffic-referrals/outgoing?web_source=desktop'}
  prior_deprecations:
  - {what: Demographics 1.0 endpoints, announced: '2024-12-31', effective: '2025-01-01', source: 'https://developers.similarweb.com/changelog/demographics-10-endpoints-will-be-deprecated-on-010125'}

deprecated_operations:
  note: >-
    No operation in openapi/ carries `deprecated: true`, but the V5 migration table lists
    several of the captured paths as sunsetting on 2026-10-06.
  by_migration_table:
  - openapi/similarweb-traffic-sources-api-openapi.yml#getTrafficSourcesOverview
  spec_flagged: []

sla:
  url: null
  uptime_target: null
  note: >-
    No public SLA or uptime commitment page was found. Enterprise agreements are described
    as negotiated ("Enterprise SLA and support" appears in plan collateral) but nothing is
    published.

status_page: null
status_page_note: >-
  Probed https://status.similarweb.com/ (DNS does not resolve) and searched the docs,
  support and marketing surfaces. Similarweb publishes no public status page, so an agent
  or integrator has no incident feed to subscribe to.

support:
  help_center: https://support.similarweb.com/hc/en-us
  developer_help: https://developers.similarweb.com/docs/getting-help
  contact: https://www.similarweb.com/corp/contact-support/

x-evidence:
  fetched: '2026-08-13'
  probes:
  - {url: https://docs.similarweb.com/api-v5/guides/rest-api-data-version-migration.md, http_status: 200}
  - {url: https://developers.similarweb.com/changelog.rss, http_status: 200}
  - {url: 'https://status.similarweb.com/', http_status: 0, note: DNS does not resolve}