diff --git a/cli/search.ml b/cli/search.ml
index 820b3181..f306d069 100644
--- a/cli/search.ml
+++ b/cli/search.ml
@@ -17,6 +17,8 @@ let string_of_kind =
   | Constructor _ -> "cons"
   | Field _ -> "field"
   | Val _ -> "val"
+  | Page -> "page"
+  | Impl -> "source"
 
 let print_result ~print_cost ~print_docstring ~no_rhs (elt : Db.Entry.t) =
   let cost = if print_cost then string_of_int elt.cost ^ " " else "" in
diff --git a/db/dune b/db/dune
index 2f917f09..e3cb6f42 100644
--- a/db/dune
+++ b/db/dune
@@ -1,2 +1,3 @@
 (library
- (name db))
+ (name db)
+ (libraries fmt))
diff --git a/db/entry.ml b/db/entry.ml
index 17c9c1c9..1e9e7e0d 100644
--- a/db/entry.ml
+++ b/db/entry.ml
@@ -6,7 +6,9 @@ let non_empty_string s =
 
 module Kind = struct
   type t =
-    | Doc
+    | Doc (** Standalone doc comment *)
+    | Page (** Mld page *)
+    | Impl (** Source page *)
     | Module
     | Module_type
     | Class
@@ -26,7 +28,7 @@ module Kind = struct
     match t with
     | Val typ | Extension_constructor typ | Exception typ | Constructor typ | Field typ ->
       Some typ
-    | Doc | Module | Module_type | Class | Class_type | Method | Type_decl _
+    | Doc | Page | Impl | Module | Module_type | Class | Class_type | Method | Type_decl _
     | Type_extension ->
       None
 end
@@ -54,6 +56,17 @@ type t =
   ; pkg : Package.t
   }
 
+let pp fmt { name; rhs; url; kind; cost; doc_html; pkg } =
+  Format.fprintf
+    fmt
+    "{ name = %s ; rhs = %a ; url = %s ; kind = . ; cost = %d ; doc_html = %s ; pkg = . }\n"
+    name
+    (Fmt.option Fmt.string)
+    rhs
+    url
+    cost
+    doc_html
+
 let string_compare_shorter a b =
   match Int.compare (String.length a) (String.length b) with
   | 0 -> String.compare a b
diff --git a/db/entry.mli b/db/entry.mli
index 4cc1904e..a88319b0 100644
--- a/db/entry.mli
+++ b/db/entry.mli
@@ -1,6 +1,8 @@
 module Kind : sig
   type t =
-    | Doc
+    | Doc (** Standalone doc comment *)
+    | Page (** Mld page *)
+    | Impl (** Source page *)
     | Module
     | Module_type
     | Class
@@ -38,6 +40,8 @@ type t =
   ; pkg : Package.t
   }
 
+val pp : t Fmt.t
+
 val v
   :  name:string
   -> kind:Kind.t
diff --git a/dune-project b/dune-project
index 6b85aa6f..d5df3c2b 100644
--- a/dune-project
+++ b/dune-project
@@ -25,7 +25,7 @@
  (synopsis "Search engine for OCaml documentation")
  (depends
   (ocaml (>= 4.0.8))
-  (odoc (>= 2.4.0))
+  (odoc (>= 3.0.0))
   (base64 (>= 3.5.1))
   (bigstringaf (>= 0.9.1))
   (js_of_ocaml (>= 5.6.0))
diff --git a/index/index.ml b/index/index.ml
index 10c017b6..28f1a327 100644
--- a/index/index.ml
+++ b/index/index.ml
@@ -1,19 +1,32 @@
+let handle_file register file =
+  let ( >>= ) = Result.bind in
+  let open Odoc_odoc in
+  let open Odoc_index in
+  match Fpath.get_ext file with
+  | ".odoc-index" -> Odoc_file.load_index file >>= fun index -> Ok (register index)
+  | ".odocl" ->
+    Odoc_file.load file
+    >>= fun unit' ->
+    (match unit' with
+     | { Odoc_file.content = Unit_content unit'; _ } when unit'.hidden ->
+       Error (`Msg "Hidden units are ignored when generating an index")
+     | { content = Unit_content u; _ } -> Ok (register [ Skeleton.from_unit u ])
+     | { content = Page_content p; _ } -> Ok (register [ Skeleton.from_page p ])
+     | _ ->
+       Error (`Msg "Only pages and unit are allowed as input when generating an index"))
+  | _ ->
+    Error
+      (`Msg "Only .odocl and .odoc-index are allowed as input when generating an index")
+
 let index_file register filename =
   match Fpath.of_string filename with
   | Error (`Msg msg) -> Format.printf "FILE ERROR %s: %s@." filename msg
   | Ok file ->
     let open Odoc_model in
-    let page p =
-      let id = p.Lang.Page.name in
-      Fold.page ~f:(register (id :> Paths.Identifier.t)) () p
-    in
-    let unit u =
-      let id = u.Lang.Compilation_unit.id in
-      Fold.unit ~f:(register (id :> Paths.Identifier.t)) () u
-    in
-    (match Odoc_odoc.Indexing.handle_file ~page ~unit file with
+    (match handle_file register file with
      | Ok result -> result
-     | Error (`Msg msg) -> Format.printf "Odoc warning or error %s: %s@." filename msg)
+     | Error (`Msg msg) ->
+       Format.printf "Odoc warning or error %a: %s@." Fpath.pp file msg)
 
 let main
   files
@@ -29,17 +42,18 @@ let main
   let module Storage = (val Db_store.storage_module db_format) in
   let db = Db_writer.make () in
   let no_pkg = Db.Entry.Package.v ~name:"" ~version:"" in
-  let register ~pkg ~favourite id () item =
+  let register ~pkg ~favourite =
     List.iter
-      (Load_doc.register_entry
-         ~db
-         ~index_docstring
-         ~index_name
-         ~type_search
-         ~favourite
-         ~favoured_prefixes
-         ~pkg)
-      (Odoc_search.Entry.entries_of_item id item)
+    @@ Odoc_utils.Tree.iter
+         ~f:
+           (Load_doc.register_entry
+              ~db
+              ~index_docstring
+              ~index_name
+              ~type_search
+              ~favourite
+              ~favoured_prefixes
+              ~pkg)
   in
   let files =
     match file_list with
@@ -109,7 +123,7 @@ let odoc_favourite_file =
   Arg.(value & opt_all file [] & info [ "favoured" ] ~doc)
 
 let odoc_files =
-  let doc = "Path to a .odocl file" in
+  let doc = "Path to a .odocl file or a .odoc-index file" in
   Arg.(value & (pos_all file [] @@ info ~doc ~docv:"ODOCL_FILE" []))
 
 let term =
diff --git a/index/load_doc.ml b/index/load_doc.ml
index 3aa96025..1a0b9705 100644
--- a/index/load_doc.ml
+++ b/index/load_doc.ml
@@ -99,7 +99,7 @@ let searchable_type_of_constructor args res =
 let searchable_type_of_record parent_type type_ =
   Odoc_model.Lang.TypeExpr.Arrow (None, parent_type, type_)
 
-let convert_kind ~db (Odoc_search.Entry.{ kind; _ } as entry) =
+let convert_kind ~db (Odoc_index.Entry.{ kind; _ } as entry) =
   match kind with
   | TypeDecl _ -> Entry.Kind.Type_decl (Odoc_search.Html.typedecl_params_of_entry entry)
   | Value { value = _; type_ } ->
@@ -121,13 +121,16 @@ let convert_kind ~db (Odoc_search.Entry.{ kind; _ } as entry) =
     let typ = searchable_type_of_record parent_type type_ in
     let typ = Db_writer.type_of_odoc ~db typ in
     Entry.Kind.Field typ
-  | Doc _ -> Doc
+  | Doc -> Doc
+  | Dir -> Doc
+  | Page _ -> Doc
   | Class_type _ -> Class_type
   | Method _ -> Method
   | Class _ -> Class
   | TypeExtension _ -> Type_extension
-  | Module -> Entry.Kind.Module
-  | ModuleType -> Module_type
+  | Module _ -> Entry.Kind.Module
+  | ModuleType _ -> Module_type
+  | Impl -> Doc
 
 let register_type_expr ~db elt typ =
   let type_polarities = Db.Type_polarity.of_typ ~any_is_poly:true typ in
@@ -142,7 +145,7 @@ let register_kind ~db elt =
 let rec categorize id =
   let open Odoc_model.Paths in
   match id.Identifier.iv with
-  | `CoreType _ | `CoreException _ | `Root _ | `Page _ | `LeafPage _ -> `definition
+  | `Root _ | `Page _ | `LeafPage _ -> `definition
   | `ModuleType _ -> `declaration
   | `Parameter _ -> `ignore (* redundant with indexed signature *)
   | ( `InstanceVariable _ | `Method _ | `Field _ | `Result _ | `Label _ | `Type _
@@ -150,11 +153,11 @@ let rec categorize id =
     | `ExtensionDecl _ | `Module _ ) as x ->
     let parent = Identifier.label_parent { id with iv = x } in
     categorize (parent :> Identifier.Any.t)
-  | `AssetFile _ | `SourceDir _ | `SourceLocationMod _ | `SourceLocation _ | `SourcePage _
+  | `AssetFile _ | `SourceLocationMod _ | `SourceLocation _ | `SourcePage _
   | `SourceLocationInternal _ ->
     `ignore (* unclear what to do with those *)
 
-let categorize Odoc_search.Entry.{ id; _ } =
+let categorize Odoc_index.Entry.{ id; _ } =
   match id.iv with
   | `ModuleType (parent, _) ->
     (* A module type itself is not *from* a module type, but it might be if one
@@ -171,7 +174,7 @@ let register_entry
   ~favoured_prefixes
   ~pkg
   ~cat
-  (Odoc_search.Entry.{ id; doc; kind } as entry)
+  (Odoc_index.Entry.{ id; doc; kind } as entry)
   =
   let module Sherlodoc_entry = Entry in
   let open Odoc_search in
@@ -185,7 +188,7 @@ let register_entry
   let rhs = Html.rhs_of_kind kind in
   let kind = convert_kind ~db entry in
   let cost = cost ~name ~kind ~doc_html ~rhs ~cat ~favourite ~favoured_prefixes in
-  let url = Result.get_ok (Html.url id) in
+  let url = Html.url entry in
   let elt = Sherlodoc_entry.v ~name ~kind ~rhs ~doc_html ~cost ~url ~pkg () in
   if index_docstring then register_doc ~db elt doc_txt ;
   if index_name && kind <> Doc then register_full_name ~db elt ;
@@ -199,15 +202,15 @@ let register_entry
   ~favourite
   ~favoured_prefixes
   ~pkg
-  (Odoc_search.Entry.{ id; kind; _ } as entry)
+  (Odoc_index.Entry.{ id; kind; _ } as entry)
   =
   let cat = categorize entry in
   let is_pure_documentation =
     match kind with
-    | Doc _ -> true
+    | Doc | Page _ | Dir | Impl -> true
     | _ -> false
   in
-  if is_pure_documentation || cat = `ignore || Odoc_model.Paths.Identifier.is_internal id
+  if is_pure_documentation || cat = `ignore || Odoc_model.Paths.Identifier.is_hidden id
   then ()
   else
     register_entry
diff --git a/index/load_doc.mli b/index/load_doc.mli
index 4012b9bf..a2a11126 100644
--- a/index/load_doc.mli
+++ b/index/load_doc.mli
@@ -6,7 +6,7 @@ val register_entry
   -> favourite:bool
   -> favoured_prefixes:string list
   -> pkg:Db.Entry.Package.t
-  -> Odoc_search.Entry.t
+  -> Odoc_index.Entry.t
   -> unit
 (** [register_entry ~db ~index_name ~type_search ~index_docstring e] register
     the entry [e] in [db]. *)
diff --git a/index/typename.ml b/index/typename.ml
index 3f052927..5d3af2b3 100644
--- a/index/typename.ml
+++ b/index/typename.ml
@@ -5,7 +5,6 @@ module ModuleName = Odoc_model.Names.ModuleName
 
 let rec show_ident_long h (r : Identifier.t_pv Identifier.id) =
   match r.iv with
-  | `CoreType n -> Format.fprintf h "Stdlib.%s" (TypeName.to_string n)
   | `Type (md, n) -> Format.fprintf h "%a.%s" show_signature md (TypeName.to_string n)
   | _ -> Format.fprintf h "%S" (r |> Identifier.fullname |> String.concat ".")
 
@@ -19,13 +18,23 @@ and show_signature h sig_ =
   | `ModuleType (_, p) ->
     Format.fprintf h "%s" (Odoc_model.Names.ModuleTypeName.to_string p)
 
-let show_type_name_verbose h : Path.Type.t -> _ = function
+let rec show_type_name_verbose h : Path.Type.t -> _ = function
   | `Resolved t ->
-    Format.fprintf h "%a" show_ident_long Path.Resolved.(identifier (t :> t))
+    (match Path.Resolved.(identifier (t :> t)) with
+     | Some i -> Format.fprintf h "%a" show_ident_long i
+     | None ->
+       (match t with
+        | `CoreType n -> Format.fprintf h "%s" (Odoc_model.Names.TypeName.to_string n)
+        | _ -> Format.fprintf h "%s" "Core type"))
   | `Identifier (path, _hidden) ->
     let name = String.concat "." @@ Identifier.fullname path in
     Format.fprintf h "%s" name
-  | `Dot (mdl, x) ->
-    Format.fprintf h "%s.%s" (Odoc_document.Url.render_path (mdl :> Path.t)) x
+  | `DotT (mdl, x) ->
+    Format.fprintf
+      h
+      "%s.%s"
+      (Odoc_document.Url.render_path (mdl :> Path.t))
+      (Odoc_model.Names.TypeName.to_string x)
+  | `SubstitutedT x -> show_type_name_verbose h x
 
 let to_string t = Format.asprintf "%a" show_type_name_verbose t
diff --git a/jsoo/main.ml b/jsoo/main.ml
index d14fb229..1f7315ea 100644
--- a/jsoo/main.ml
+++ b/jsoo/main.ml
@@ -81,6 +81,8 @@ let string_of_kind =
   let open Odoc_html_frontend in
   function
   | Db.Entry.Kind.Doc -> kind_doc
+  | Page -> kind_doc
+  | Impl -> kind_impl
   | Type_decl _ -> kind_typedecl
   | Module -> kind_module
   | Exception _ -> kind_exception
diff --git a/jsoo/odoc_html_frontend.ml b/jsoo/odoc_html_frontend.ml
index c24c6ba2..9496d0d2 100644
--- a/jsoo/odoc_html_frontend.ml
+++ b/jsoo/odoc_html_frontend.ml
@@ -49,3 +49,4 @@ let kind_constructor = "cons"
 let kind_field = "field"
 let kind_value = "val"
 let kind_extension = "ext"
+let kind_impl = "source"
diff --git a/sherlodoc.opam b/sherlodoc.opam
index c3b67571..46be9538 100644
--- a/sherlodoc.opam
+++ b/sherlodoc.opam
@@ -10,7 +10,7 @@ bug-reports: "https://github.com/art-w/sherlodoc/issues"
 depends: [
   "dune" {>= "3.5"}
   "ocaml" {>= "4.0.8"}
-  "odoc" {>= "2.4.0"}
+  "odoc" {>= "3.0.0"}
   "base64" {>= "3.5.1"}
   "bigstringaf" {>= "0.9.1"}
   "js_of_ocaml" {>= "5.6.0"}
diff --git a/test/cram/base_cli.t b/test/cram/base_cli.t
index f7cea656..011a36a9 100644
--- a/test/cram/base_cli.t
+++ b/test/cram/base_cli.t
@@ -262,12 +262,12 @@ Partial name search:
   175 val Base.String.uppercase : t -> t
   176 type Base.String.Caseless.t = t
   176 val Base.String.capitalize : t -> t
-  177 mod Base.StringLabels
   177 mod Caml.StringLabels
   177 val Base.String.append : t -> t -> t
   177 val Base.Exn.to_string_mach : t -> string
   177 val Base.Info.to_string_hum : t -> string
   177 val Base.Sign.to_string_hum : t -> string
+  178 val Base.Info.to_string_mach : t -> string
   $ sherlodoc search --print-cost "tring"
   177 type Base.string = String.t
   182 type Base.String.t = string
diff --git a/test/cram/cli.t/run.t b/test/cram/cli.t/run.t
index 93d2faf3..c5e31762 100644
--- a/test/cram/cli.t/run.t
+++ b/test/cram/cli.t/run.t
@@ -3,9 +3,10 @@
   $ odoc compile -I . page.mld
   $ odoc link -I . main.odoc
   $ odoc link -I . page-page.odoc
+  $ odoc compile-index -o index.odoc-index --root ./
   $ export SHERLODOC_DB=db.bin
   $ export SHERLODOC_FORMAT=marshal
-  $ sherlodoc index $(find . -name '*.odocl')
+  $ sherlodoc index index.odoc-index
   $ sherlodoc search "unique_name"
   val Main.unique_name : foo
   $ sherlodoc search "multiple_hit"
@@ -59,6 +60,8 @@
   $ sherlodoc search "modtype"
   sig Main.Modtype
   val Main.Modtype.v_modtype : foo
+  $ sherlodoc search "extensible"
+  type Main.extensible_type = ..
   $ sherlodoc search "S"
   mod Main.S_to_S1
   sig Main.S
@@ -67,7 +70,6 @@
   mod Main.List
   mod Main.Nest
   type 'a Main.list
-  type Main.MyExtension
   cons Main.MyExtension : moo -> extensible_type
   val Main.consume : moo -> unit
   val Main.Map.to_list : foo
diff --git a/test/cram/multi_package.t b/test/cram/multi_package.t
index e0dd47ce..884961a9 100644
--- a/test/cram/multi_package.t
+++ b/test/cram/multi_package.t
@@ -264,12 +264,12 @@ Partial name search:
   175 val Base.String.uppercase : t -> t
   176 type Base.String.Caseless.t = t
   176 val Base.String.capitalize : t -> t
-  177 mod Base.StringLabels
   177 mod Caml.StringLabels
   177 val Base.String.append : t -> t -> t
   177 val Base.Exn.to_string_mach : t -> string
   177 val Base.Info.to_string_hum : t -> string
   177 val Base.Sign.to_string_hum : t -> string
+  178 val Base.Info.to_string_mach : t -> string
   $ sherlodoc search --print-cost "base strin"
   162 type Base.string = String.t
   174 type Base.Export.string = String.t
@@ -289,13 +289,13 @@ Partial name search:
   190 val Base.String.uppercase : t -> t
   191 type Base.String.Caseless.t = t
   191 val Base.String.capitalize : t -> t
-  192 mod Base.StringLabels
   192 val Base.String.append : t -> t -> t
   192 val Base.Exn.to_string_mach : t -> string
   192 val Base.Info.to_string_hum : t -> string
   192 val Base.Sign.to_string_hum : t -> string
   193 val Base.Error.to_string_hum : t -> string
   193 val Base.Info.to_string_mach : t -> string
+  194 val Base.Error.to_string_mach : t -> string
 
   $ sherlodoc search --print-cost "tring"
   177 type Base.string = String.t
@@ -348,5 +348,5 @@ Partial name search:
   212 val Base.String.ascending : t -> t -> int
   212 val Base.String.split_lines : t -> t list
   212 val Base.Sys.max_string_length : int
-  214 val Base.String.common_prefix : t list -> t
+  214 val Base.String.common_suffix : t list -> t
 
diff --git a/test/cram/prefix_favouritism.t b/test/cram/prefix_favouritism.t
index f9db8ed7..1b98e182 100644
--- a/test/cram/prefix_favouritism.t
+++ b/test/cram/prefix_favouritism.t
@@ -25,9 +25,9 @@
   165 val Base.List.ignore_m : 'a t -> unit t
   166 val Base.List.drop : 'a t -> int -> 'a t
   166 val Base.List.take : 'a t -> int -> 'a t
-  175 mod Base.ListLabels
   175 mod Caml.ListLabels
   394 mod Base
+  397 type Base.Nothing.t = 
   $ sherlodoc index --favoured-prefixes=Base $ODOCLS > /dev/null
   $ sherlodoc search --print-cost "list"
   81 type 'a Base.list = 'a List.t
@@ -50,11 +50,11 @@
   115 val Base.List.ignore_m : 'a t -> unit t
   116 val Base.List.drop : 'a t -> int -> 'a t
   116 val Base.List.take : 'a t -> int -> 'a t
-  125 mod Base.ListLabels
   344 mod Base
   347 type Base.Nothing.t = 
   362 val Base.String.append : t -> t -> t
   364 val Base.Int.ascending : t -> t -> int
+  365 val Base.Bool.ascending : t -> t -> int
   $ sherlodoc index --favoured-prefixes=Caml $ODOCLS > /dev/null
   $ sherlodoc search --print-cost "list"
   104 mod Caml.List
@@ -80,8 +80,8 @@
   165 val Base.List.ignore_m : 'a t -> unit t
   166 val Base.List.drop : 'a t -> int -> 'a t
   166 val Base.List.take : 'a t -> int -> 'a t
-  175 mod Base.ListLabels
   394 mod Base
+  397 type Base.Nothing.t = 
   $ sherlodoc index --favoured-prefixes=Base,Caml $ODOCLS > /dev/null
   $ sherlodoc search --print-cost "list"
   81 type 'a Base.list = 'a List.t
@@ -105,10 +105,10 @@
   115 val Base.List.ignore_m : 'a t -> unit t
   116 val Base.List.drop : 'a t -> int -> 'a t
   116 val Base.List.take : 'a t -> int -> 'a t
-  125 mod Base.ListLabels
   125 mod Caml.ListLabels
   344 mod Base
   347 type Base.Nothing.t = 
+  362 val Base.String.append : t -> t -> t
   $ sherlodoc index $ODOCLS --favoured-prefixes "" > /dev/null
   $ sherlodoc search --print-cost "list"
   131 type 'a Base.list = 'a List.t
@@ -133,8 +133,8 @@
   165 val Base.List.ignore_m : 'a t -> unit t
   166 val Base.List.drop : 'a t -> int -> 'a t
   166 val Base.List.take : 'a t -> int -> 'a t
-  175 mod Base.ListLabels
   175 mod Caml.ListLabels
   394 mod Base
+  397 type Base.Nothing.t = 
 
 Partial name search: