diff --git a/qurator/dinglehopper/__init__.py b/qurator/dinglehopper/__init__.py
index fd309dc..dc45a8f 100644
--- a/qurator/dinglehopper/__init__.py
+++ b/qurator/dinglehopper/__init__.py
@@ -3,4 +3,8 @@ from .extracted_text import *
 from .character_error_rate import *
 from .word_error_rate import *
 from .align import *
-from .flexible_character_accuracy import flexible_character_accuracy, split_matches
+from .flexible_character_accuracy import (
+    flexible_character_accuracy,
+    split_matches,
+    Match,
+)
diff --git a/qurator/dinglehopper/cli.py b/qurator/dinglehopper/cli.py
index b717618..46fc0b0 100644
--- a/qurator/dinglehopper/cli.py
+++ b/qurator/dinglehopper/cli.py
@@ -14,7 +14,7 @@ from .ocr_files import extract
 from .config import Config
 
 
-def gen_diff_report(gt_in, ocr_in, css_prefix, joiner, none, ops=None):
+def gen_diff_report(gt_in, ocr_in, css_prefix, joiner, none, matches=None):
     gtx = ""
     ocrx = ""
 
@@ -42,7 +42,27 @@ def gen_diff_report(gt_in, ocr_in, css_prefix, joiner, none, ops=None):
         else:
             return "{html_t}".format(html_t=html_t)
 
-    if isinstance(gt_in, ExtractedText):
+    ops, ocr_ids = None, None
+    if matches:
+        gt_things, ocr_things, ops = split_matches(matches)
+        # we have to reconstruct the order of the ocr because we mixed it for fca
+        ocr_lines = [match.ocr for match in matches]
+        ocr_lines_sorted = sorted(ocr_lines, key=lambda x: x.line + x.start / 10000)
+
+        ocr_line_region_id = {}
+        pos = 0
+        for ocr_line in ocr_lines_sorted:
+            if ocr_line.line not in ocr_line_region_id.keys():
+                ocr_line_region_id[ocr_line.line] = ocr_in.segment_id_for_pos(pos)
+            pos += ocr_line.length
+
+        ocr_ids = {None: None}
+        pos = 0
+        for ocr_line in ocr_lines:
+            for _ in ocr_line.text:
+                ocr_ids[pos] = ocr_line_region_id[ocr_line.line]
+                pos += 1
+    elif isinstance(gt_in, ExtractedText):
         if not isinstance(ocr_in, ExtractedText):
             raise TypeError()
         # XXX splitting should be done in ExtractedText
@@ -61,10 +81,13 @@ def gen_diff_report(gt_in, ocr_in, css_prefix, joiner, none, ops=None):
         if g != o:
             css_classes = "{css_prefix}diff{k} diff".format(css_prefix=css_prefix, k=k)
             if isinstance(gt_in, ExtractedText):
-                gt_id = gt_in.segment_id_for_pos(g_pos) if g is not None else None
-                ocr_id = ocr_in.segment_id_for_pos(o_pos) if o is not None else None
                 # Deletions and inserts only produce one id + None, UI must
                 # support this, i.e. display for the one id produced
+                gt_id = gt_in.segment_id_for_pos(g_pos) if g else None
+                if ocr_ids:
+                    ocr_id = ocr_ids[o_pos]
+                else:
+                    ocr_id = ocr_in.segment_id_for_pos(o_pos) if o else None
 
         gtx += joiner + format_thing(g, css_classes, gt_id)
         ocrx += joiner + format_thing(o, css_classes, ocr_id)
@@ -111,15 +134,9 @@ def process(gt, ocr, report_prefix, *, metrics="cer,wer", textequiv_level="regio
             gt_words, ocr_words, css_prefix="w", joiner=" ", none="⋯"
         )
     if "fca" in metrics:
-        fca, fca_matches = flexible_character_accuracy(gt_text.text, ocr_text.text)
-        fca_gt_segments, fca_ocr_segments, ops = split_matches(fca_matches)
+        fca, fca_matches = flexible_character_accuracy(gt_text, ocr_text)
         fca_diff_report = gen_diff_report(
-            fca_gt_segments,
-            fca_ocr_segments,
-            css_prefix="c",
-            joiner="",
-            none="·",
-            ops=ops,
+            gt_text, ocr_text, css_prefix="c", joiner="", none="·", matches=fca_matches
         )
 
     def json_float(value):
diff --git a/qurator/dinglehopper/flexible_character_accuracy.py b/qurator/dinglehopper/flexible_character_accuracy.py
index 7865dd1..349384c 100644
--- a/qurator/dinglehopper/flexible_character_accuracy.py
+++ b/qurator/dinglehopper/flexible_character_accuracy.py
@@ -17,7 +17,9 @@ from functools import lru_cache, reduce
 from itertools import product, takewhile
 from typing import List, Tuple, Optional
 
-from . import editops
+from multimethod import multimethod
+
+from . import editops, ExtractedText
 
 if sys.version_info.minor == 5:
     from .flexible_character_accuracy_ds_35 import (
@@ -35,6 +37,22 @@ else:
     )
 
 
+@multimethod
+def flexible_character_accuracy(
+    gt: ExtractedText, ocr: ExtractedText
+) -> Tuple[float, List[Match]]:
+    """Calculate the flexible character accuracy.
+
+    Reference: contains steps 1-7 of the flexible character accuracy algorithm.
+
+    :param gt: The ground truth text.
+    :param ocr: The text to compare the ground truth with.
+    :return: Score between 0 and 1 and match objects.
+    """
+    return flexible_character_accuracy(gt.text, ocr.text)
+
+
+@multimethod
 def flexible_character_accuracy(gt: str, ocr: str) -> Tuple[float, List[Match]]:
     """Calculate the flexible character accuracy.
 
@@ -359,7 +377,7 @@ def split_matches(matches: List[Match]) -> Tuple[List[str], List[str], List[List
     :param matches: List of match objects.
     :return: List of ground truth segments, ocr segments and editing operations.
     """
-    matches = sorted(matches, key=lambda x: x.gt.line + x.gt.start / 10000)
+    matches = sorted(matches, key=lambda m: m.gt.line + m.gt.start / 10000)
     line = 0
     gt, ocr, ops = [], [], []
     for match in matches:
@@ -410,4 +428,4 @@ class Part(PartVersionSpecific):
         """
         text = self.text[rel_start:rel_end]
         start = self.start + rel_start
-        return Part(text=text, line=self.line, start=start)
+        return Part(**{**self._asdict(), "text": text, "start": start})
diff --git a/qurator/dinglehopper/tests/test_flexible_character_accuracy.py b/qurator/dinglehopper/tests/test_flexible_character_accuracy.py
index 2f6d702..3ade597 100644
--- a/qurator/dinglehopper/tests/test_flexible_character_accuracy.py
+++ b/qurator/dinglehopper/tests/test_flexible_character_accuracy.py
@@ -10,6 +10,7 @@ DOI: 10.1016/j.patrec.2020.02.003
 """
 
 import pytest
+from lxml import etree as ET
 
 from ..flexible_character_accuracy import *
 
@@ -101,11 +102,39 @@ def extended_case_to_text(gt, ocr):
 
 
 @pytest.mark.parametrize(CASE_ARGS, [*SIMPLE_CASES, *COMPLEX_CASES])
-def test_flexible_character_accuracy_simple(gt, ocr, first_line_score, all_line_score):
+def test_flexible_character_accuracy_str(gt, ocr, first_line_score, all_line_score):
     score, _ = flexible_character_accuracy(gt, ocr)
     assert score == pytest.approx(all_line_score)
 
 
+@pytest.mark.parametrize(CASE_ARGS, [*SIMPLE_CASES, *COMPLEX_CASES])
+def test_flexible_character_accuracy_xml(gt, ocr, first_line_score, all_line_score):
+    def get_extracted_text(text: str):
+        xml = '<?xml version="1.0"?>'
+        ns = "http://schema.primaresearch.org/PAGE/gts/pagecontent/2018-07-15"
+
+        textline_tmpl = (
+            '<TextLine id="l{0}"><TextEquiv><Unicode>{1}'
+            "</Unicode></TextEquiv></TextLine>"
+        )
+        xml_tmpl = '{0}<TextRegion id="0" xmlns="{1}">{2}</TextRegion>'
+
+        textlines = [
+            textline_tmpl.format(i, line) for i, line in enumerate(text.splitlines())
+        ]
+        xml_text = xml_tmpl.format(xml, ns, "".join(textlines))
+        root = ET.fromstring(xml_text)
+        extracted_text = ExtractedText.from_text_segment(
+            root, {"page": ns}, textequiv_level="line"
+        )
+        return extracted_text
+
+    gt_text = get_extracted_text(gt)
+    ocr_text = get_extracted_text(ocr)
+    score, _ = flexible_character_accuracy(gt_text, ocr_text)
+    assert score == pytest.approx(all_line_score)
+
+
 @pytest.mark.parametrize(
     "config,ocr",
     [