diff --git a/Sources/Parsing/ParserPrinters/Indexed.swift b/Sources/Parsing/ParserPrinters/Indexed.swift
new file mode 100644
index 0000000000..70f439033d
--- /dev/null
+++ b/Sources/Parsing/ParserPrinters/Indexed.swift
@@ -0,0 +1,31 @@
+extension Parsers {
+  /// A parser of a collection that returns a base parser's output as well as the index range of the
+  /// parsed input.
+  public struct Indexed<Base>: Parser
+  where Base: Parser, Base.Input: Collection {
+    public let base: Base
+
+    @inlinable
+    init(_ base: Base) {
+      self.base = base
+    }
+
+    @inlinable
+    public func parse(
+      _ input: inout Base.Input
+    ) throws -> (output: Base.Output, indices: Range<Base.Input.Index>) {
+      let startIndex = input.startIndex
+      let output = try base.parse(&input)
+      return (output, startIndex..<input.startIndex)
+    }
+  }
+}
+
+extension Parser where Input: Collection {
+  /// A parser of a collection that returns a base parser's output as well as the index range of the
+  /// parsed input.
+  @inlinable
+  public func indexed() -> Parsers.Indexed<Self> {
+    Parsers.Indexed(self)
+  }
+}
diff --git a/Tests/ParsingTests/IndexedTests.swift b/Tests/ParsingTests/IndexedTests.swift
new file mode 100644
index 0000000000..270dd3d294
--- /dev/null
+++ b/Tests/ParsingTests/IndexedTests.swift
@@ -0,0 +1,46 @@
+import Parsing
+import XCTest
+
+private struct Output: Equatable {
+  var username: Substring
+  var range: Range<String.Index>
+}
+
+final class IndexedTests: XCTestCase {
+  func testStringHappyPath() throws {
+    let input = "Hi @BlobJr; please call @BlobSr when you get a chance. Thanks."
+    let parser: some Parser<Substring.UTF8View, [Output]> = Many {
+      Skip {
+        PrefixUpTo("@".utf8)
+      }
+
+      From(.substring) {
+        Parse {
+          "@"
+
+          Prefix(while: { $0.isLetter || $0.isNumber })
+        }
+        .indexed()
+      }
+      .map(Output.init)
+    } terminator: {
+      Rest()
+    }
+    let usernames = try parser.parse(input)
+    XCTAssertEqual(
+      usernames,
+      [
+        Output(
+          username: "BlobJr",
+          range: input
+            .index(input.startIndex, offsetBy: 3)..<input.index(input.startIndex, offsetBy: 10)
+        ),
+        Output(
+          username: "BlobSr",
+          range: input
+            .index(input.startIndex, offsetBy: 24)..<input.index(input.startIndex, offsetBy: 31)
+        )
+      ]
+    )
+  }
+}