# Atlas Search searchAfter pagination > Source-anchored research for Atlas Search searchAfter pagination. Run status: COMPLETED. Parent: [MongoDB Query Shape Optimization: Sort, Pagination, Operators and Sharded Targeting](https://llms-explorer.com/tree/mongodb-query-shape-optimization-sort-pagination-operators-and-sharded-targeting/) · 5 facets · 10 facts · page: https://llms-explorer.com/tree/atlas-search-searchafter-pagination/ ## Definitions - A sequence token is an ordering reference, not a database snapshot. MongoDB says writes or deletes between requests can change result order. Its September 25, 2026 engineering post also describes BM25 corpus statistics changing across Search replicas and moving results across page boundaries, which can produce duplicates or skips. (high confidence) (verified as of 2026-09-25) — [source](https://www.mongodb.com/docs/search/query/paginate-results.md) ## How it works - The .NET/C# driver exposes `SearchOptions.SearchAfter` and a `MetaSearchSequenceToken` projection builder for this cursor flow. Its guide applies the token to another search with the same matching criteria. (high confidence) — [source](https://www.mongodb.com/docs/drivers/csharp/current/atlas-search.md) - A 2024 Go community thread proposes that using unordered `bson.M` for a compound `$search.sort` can change field order and trigger intermittent pagination errors; it suggests ordered `bson.D`. The thread does not confirm that this suggestion fixed the report. (low confidence) — [source](https://www.mongodb.com/community/forums/t/occur-error-when-paginate-document-result-used-search-index-in-golang/269279) - MongoDB Search does not guarantee the order of results tied on a sort value, which can cause repeated or missed results across page boundaries. Sort by a unique field or add a unique secondary sort as a tiebreaker. (high confidence) — [source](https://www.mongodb.com/docs/search/query/paginate-results.md) ## Problems, failure modes and limitations - For deterministic page boundaries, add a unique field as a secondary sort when the main sort can tie, and prefer immutable sort fields. MongoDB warns that tied results have no guaranteed order and that updates or deletes between requests can change the order; one community user confirmed that adding a unique sort fixed a searchBefore pagination failure caused by tied scores. (high confidence) — [source](https://www.mongodb.com/docs/search/query/paginate-results.md) - Use `searchAfter` for sequential traversal. For a jump from a known page, resume from that page's last token and combine it with `$skip` and `$limit` to skip only the intervening results. Saving first and last tokens for visited pages also supports returning to those page boundaries without starting from the beginning. (high confidence) — [source](https://www.mongodb.com/docs/search/query/paginate-results.md) ## Comparisons and alternatives - MongoDB reports StableTfl as a per-field similarity option that makes scores for the same query and document consistent across replicas. Its BEIR benchmark averaged NDCG@10 of 0.315 for StableTfl versus 0.346 for BM25 across 21 datasets, so the reported tradeoff favors stable ranking over maximum relevance. (medium confidence) (verified as of 2026-09-25) — [source](https://www.mongodb.com/company/blog/engineering/same-query-same-score-consistent-ranking-with-stabletfl-atlas-search) - When pagination sorts by searchScore across dedicated Search nodes, BM25 can produce different scores as node corpora diverge, shifting page boundaries and causing duplicates or omissions. MongoDB's September 25, 2026 engineering post describes StableTfl as a per-field option that produces consistent scores across replicas, with some ranking-quality tradeoff. (medium confidence) (verified as of 2026-09-25) — [source](https://www.mongodb.com/docs/search/query/paginate-results.md) ## Facts and statements - Project the searchSequenceToken metadata value after $search to return a Base64 reference token for each result, then pass a returned token as searchAfter in the next $search query. The token can only be reused with the originating query semantics, so keep the search fields and values identical across pages. (high confidence) — [source](https://www.mongodb.com/docs/search/query/paginate-results.md) - A searchSequenceToken does not preserve a database snapshot. Inserts, deletes, and updates between requests can change result order; sorting by an immutable field such as _id helps keep later pages deterministic. (high confidence) — [source](https://www.mongodb.com/docs/search/query/paginate-results.md)