SERP Rank Change Detector

Compares two supplied search-result snapshots and returns deterministic rank gains, losses, entries, exits, URL swaps, and duplicate-result evidence without querying a search engine. It is built for SEO operations teams, search-data pipeline owners, agencies comparing controlled SERP exports. The main result is structured, deterministic evidence that can be consumed from the default dataset or an Apify automation.

When to use this Actor

• Monitor ranking gains and losses between consistently collected snapshots.
• Detect new entries, exits, and unambiguous title-based URL swaps.
• Find duplicate canonical URLs before storing or reporting SERP data.

How it works

• Validate that both bounded snapshots share an explicit query, engine, locale, and device context.
• Canonicalize HTTP(S) URLs and compare exact result identities and ranks.
• Emit deterministically sorted change, duplicate, and summary records before the completion event is charged.

The Actor validates only the declared product contract. It does not infer facts outside the supplied data or claim outcomes that the source material cannot prove.

Quick start

1. Open the Actor's Input tab or create a Task from one of the public examples.
2. Paste or adapt this bounded example.
3. Click Start and inspect the default dataset plus the output links shown on the run page.

{
  "comparisonId": "apify-actors-weekly",
  "query": "apify actors",
  "engine": "google",
  "locale": "en-US",
  "device": "desktop",
  "baseline": [
    {
      "rank": 1,
      "url": "https://example.com/guide",
      "title": "Actor Guide"
    },
    {
      "rank": 2,
      "url": "https://example.org/store",
      "title": "Actor Store"
    }
  ],
  "current": [
    {
      "rank": 1,
      "url": "https://example.org/store",
      "title": "Actor Store"
    },
    {
      "rank": 3,
      "url": "https://example.com/guide",
      "title": "Actor Guide"
    }
  ]
}

Expected result: rank-change records for the gain and loss plus one serp-summary record.

Input

The quick-start example is intentionally small. These are the material controls; the Input tab remains authoritative for the complete current schema.

Field	Purpose and format	Default	Important bounds or interaction
comparisonId	Stable caller-defined label copied into every result for routing and repeat-run reconciliation.	No implicit default	minimum length 1; maximum length 120
query	Exact search query represented by both supplied snapshots; the Actor does not execute the search.	No implicit default	minimum length 1; maximum length 500
engine	Search engine label that must match the provenance of both snapshots.	No implicit default	minimum length 1; maximum length 80
locale	Locale context shared by both snapshots so rankings from unlike markets are not silently compared.	No implicit default	minimum length 1; maximum length 80
device	Device class shared by both snapshots, such as desktop or mobile according to the schema enum.	No implicit default	minimum length 1; maximum length 80
baseline	Earlier ordered SERP rows with explicit ranks and URLs.	No implicit default	maximum items 1000
current	Later ordered SERP rows compared with baseline under the same query context.	No implicit default	maximum items 1000
maxResultsPerSnapshot	Optional lower cap applied independently to each snapshot before comparison.	No implicit default	minimum 1; maximum 1000

Unknown top-level fields and invalid field combinations fail validation rather than being guessed.

Output

The default dataset contains typed records. The run's Output tab links the dataset and any key-value-store reports declared by the current output schema.

Field	Meaning
recordType	Discriminates rank-change, duplicate-result, and serp-summary records.
comparisonId	Current dataset field.
changeType	Current dataset field.
url	Current dataset field.
previousUrl	Current dataset field.
title	Current dataset field.
baselineRank	Current dataset field.
currentRank	Current dataset field.
delta	Signed rank movement under the Actor's documented ordering semantics.
snapshot	Current dataset field.
canonicalUrl	Current dataset field.
ranks	All source ranks participating in a duplicate canonical-URL group.
engineVersion	Current dataset field.

Representative current-schema dataset item:

{
  "recordType": "rank-change",
  "comparisonId": "apify-actors-weekly",
  "changeType": "GAINED",
  "url": "https://example.org/store",
  "title": "Actor Store",
  "baselineRank": 2,
  "currentRank": 1,
  "delta": 1,
  "engineVersion": "1.0.0"
}

Equivalent valid snapshots succeed with a serp-summary record and zero rank-change records.

Pricing and billing

This Actor uses PAY_PER_EVENT; platform usage is included in event prices. A charge is eligible only after the billable unit described below is durably completed. Validation failures and the non-billable failure classes in the product contract do not emit the custom completion event. The current live policy uses the same event price at every Store tier; no tier discount is active. The Apify Pricing tab is authoritative if a later approved pricing change takes effect.

Event	What triggers it	FREE	BRONZE	SILVER	GOLD	PLATINUM	DIAMOND
serp-snapshots-compared	One baseline/current SERP snapshot pair converted into durable rank-change evidence.	$0.02000000	$0.02000000	$0.02000000	$0.02000000	$0.02000000	$0.02000000
apify-actor-start	Platform-managed Actor start event.	$0.00005000	$0.00005000	$0.00005000	$0.00005000	$0.00005000	$0.00005000

The Actor does not have Task-specific prices: public Tasks use this same live Actor pricing. Third-party costs are not implied; see the data and security section for external services actually contacted.

Limits and bounds

• Each snapshot is capped at 1,000 rows; maxResultsPerSnapshot may select a lower bound.
• Only supplied snapshots are compared; no search engine, proxy, browser, or SERP API is called.
• URL swaps require an unambiguous title match and are not guessed when candidates conflict.

These are product-facing limits, not targets. Use smaller inputs when you need faster feedback or simpler evidence.

Failure and edge-case behavior

• Invalid context, ranks, URLs, duplicate rank positions, or over-limit input fails closed before the custom event.
• An empty supplied snapshot is valid and can produce truthful entries or exits.
• Duplicate canonical URLs are represented explicitly instead of silently selecting one rank.

Operationally:

• Collect both snapshots with comparable engine, locale, device, personalization, and timing controls.
• A rank change is observation evidence only and does not imply traffic, conversion, or revenue impact.

Use with Tasks and automation

Public Tasks provide reusable saved inputs for distinct supported workflows. Start with the closest Example Task, review its visible fields and scope caveat, then save your own Task for schedules or repeated runs. Do not treat an Example Task as evidence that unsupported behavior exists.

• Compare two SERP ranking exports: Measure entries, exits, gains, losses, URL swaps, and duplicate rows between comparable safe snapshots.
• Monitor SERP rank gains and losses: Measure ranking gains and losses for URLs between two exported SERP snapshots.
• Detect SERP entries, exits, and URL swaps: Detect URLs entering or leaving an exported SERP and identify rank-slot URL swaps.

Integration and API usage

Every saved Task can be started manually, through the Apify API, or from an Apify schedule. Run-completion webhooks can notify a downstream system after output is durable. Actor-to-Actor calls should consume the typed dataset/output links instead of scraping the Store page.

• Schedule a saved comparison Task after upstream SERP collection completes.
• Use recordType, changeType, and canonicalUrl for downstream dashboards or alerts.

No third-party integration is claimed unless it is named above and supported by the current product contract.

Data, privacy, and security

• Queries, URLs, titles, and evidence are stored in the run's Apify storages according to account retention settings.
• No external service is contacted and no search credentials are required.

Set Apify storage retention and access according to the sensitivity of your inputs and outputs. This documentation does not create legal, privacy, compliance, or security certification.

Support and known limitations

• The Actor does not collect live SERPs, forecast traffic, or explain why a ranking changed.
• Different collection methods or personalization can make snapshot comparisons misleading even when the input is structurally valid.

For support, use the Actor Issues page. Include the run ID, a minimal reproducible input with sensitive values removed, the failing record or error code, and what you expected. Do not post credentials, private source files, customer data, or full confidential payloads.