diff --git a/CHANGELOG.md b/CHANGELOG.md
index b4a36ee2..25dbc196 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,50 @@
 
 - Added new models `DbrxForCausalLM`, `OlmoForCausalLM`, `Phi3ForCausalLM`, `Qwen2MoeForCausalLM` to model config.
 
+- Rows and columns in the visualization now have indices alongside tokens to facilitate index-based slicing, aggregation and alignment [#282](https://github.com/inseq-team/inseq/pull/282)
+
+- - A new `SliceAggregator` (`"slices"`) is added to allow for slicing source (in encoder-decoder) or target (in decoder-only) tokens from a `FeatureAttributionSequenceOutput` object, using the same syntax of `ContiguousSpanAggregator`. The `__getitem__` method of the `FeatureAttributionSequenceOutput` is a shortcut for this, allowing slicing with `[start:stop]` syntax. [#282](https://github.com/inseq-team/inseq/pull/282)
+
+```python
+import inseq
+from inseq.data.aggregator import SliceAggregator
+
+attrib_model = inseq.load_model("gpt2", "attention")
+input_prompt = """Instruction: Summarize this article.
+Input_text: In a quiet village nestled between rolling hills, an ancient tree whispered secrets to those who listened. One night, a curious child named Elara leaned close and heard tales of hidden treasures beneath the roots. As dawn broke, she unearthed a shimmering box, unlocking a forgotten world of wonder and magic.
+Summary:"""
+
+full_output_prompt = input_prompt + " Elara discovers a shimmering box under an ancient tree, unlocking a world of magic."
+
+out = attrib_model.attribute(input_prompt, full_output_prompt)[0]
+
+# These are all equivalent ways to slice only the input text contents
+out_sliced = out.aggregate(SliceAggregator, target_spans=(13,73))
+out_sliced = out.aggregate("slices", target_spans=(13,73))
+out_sliced = out[13:73]
+```
+
+- The `__sub__` method in `FeatureAttributionSequenceOutput` is now used as a shortcut for `PairAggregator` [#282](https://github.com/inseq-team/inseq/pull/282)
+
+
+```python
+import inseq
+
+attrib_model = inseq.load_model("gpt2", "saliency")
+
+out_male = attrib_model.attribute(
+    "The director went home because",
+    "The director went home because he was tired",
+    step_scores=["probability"]
+)[0]
+out_female = attrib_model.attribute(
+    "The director went home because",
+    "The director went home because she was tired",
+    step_scores=["probability"]
+)[0]
+(out_male - out_female).show()
+```
+
 ## 🔧 Fixes and Refactoring
 
 - Fix the issue in the attention implementation from [#268](https://github.com/inseq-team/inseq/issues/268) where non-terminal position in the tensor were set to nan if they were 0s ([#269](https://github.com/inseq-team/inseq/pull/269)).
@@ -14,6 +58,9 @@
 
 - Fix bug reported in [#266](https://github.com/inseq-team/inseq/issues/266) making `value_zeroing` unusable for SDPA attention. This enables using the method on models using SDPA attention as default (e.g. `GemmaForCausalLM`) without passing `model_kwargs={'attn_implementation': 'eager'}` ([#267](https://github.com/inseq-team/inseq/pull/267)).
 
+- The directions of generated/attributed tokens were clarified in the visualization using arrows instead of x/y [#282](https://github.com/inseq-team/inseq/pull/282)
+
+
 ## 📝 Documentation and Tutorials
 
 *No changes*
diff --git a/Makefile b/Makefile
index a03222c5..9df893fa 100644
--- a/Makefile
+++ b/Makefile
@@ -82,7 +82,7 @@ fix-style:
 
 .PHONY: check-safety
 check-safety:
-	$(PYTHON) -m safety check --full-report
+	$(PYTHON) -m safety check --full-report -i 70612
 
 .PHONY: lint
 lint: fix-style check-safety
diff --git a/inseq/data/aggregator.py b/inseq/data/aggregator.py
index ec4ad481..32265b09 100644
--- a/inseq/data/aggregator.py
+++ b/inseq/data/aggregator.py
@@ -357,9 +357,9 @@ def end_aggregation_hook(cls, attr: "FeatureAttributionSequenceOutput", **kwargs
                 assert attr.target_attributions.ndim == 2, attr.target_attributions.shape
         except AssertionError as e:
             raise RuntimeError(
-                f"The aggregated attributions should be 2-dimensional to be visualized. Found dimensions: {e.args[0]}"
-                "If you're performing intermediate aggregation and don't aim to visualize the output right away, use"
-                "do_post_aggregation_checks=False in the aggregate method to bypass this check."
+                f"The aggregated attributions should be 2-dimensional to be visualized.\nFound dimensions: {e.args[0]}"
+                "\n\nIf you're performing intermediate aggregation and don't aim to visualize the output right away, "
+                "use do_post_aggregation_checks=False in the aggregate method to bypass this check."
             ) from e
 
     @staticmethod
@@ -530,7 +530,7 @@ def format_spans(spans) -> list[tuple[int, int]]:
         return [spans] if isinstance(spans[0], int) else spans
 
     @classmethod
-    def validate_spans(cls, span_sequence: "FeatureAttributionSequenceOutput", spans: Optional[IndexSpan] = None):
+    def validate_spans(cls, span_sequence: list[TokenWithId], spans: Optional[IndexSpan] = None):
         if not spans:
             return
         allmatch = lambda l, type: all(isinstance(x, type) for x in l)
@@ -545,7 +545,7 @@ def validate_spans(cls, span_sequence: "FeatureAttributionSequenceOutput", spans
             assert (
                 span[0] >= prev_span_max
             ), f"Spans must be postive-valued, non-overlapping and in ascending order, got {spans}"
-            assert span[1] < len(span_sequence), f"Span values must be indexes of the original span, got {spans}"
+            assert span[1] <= len(span_sequence), f"Span values must be indexes of the original span, got {spans}"
             prev_span_max = span[1]
 
     @staticmethod
@@ -808,3 +808,136 @@ def aggregate_sequence_scores(attr, paired_attr, aggregate_fn, **kwargs):
             agg_fn = aggregate_fn[name] if isinstance(aggregate_fn, dict) else aggregate_fn
             out_dict[name] = agg_fn(sequence_scores, paired_attr.sequence_scores[name])
         return out_dict
+
+
+class SliceAggregator(ContiguousSpanAggregator):
+    """Slices the FeatureAttributionSequenceOutput object into a smaller one containing a subset of its elements.
+
+    Args:
+        attr (:class:`~inseq.data.FeatureAttributionSequenceOutput`): The starting attribution object.
+        source_spans (tuple of [int, int] or sequence of tuples of [int, int], optional): Spans to slice for the
+            source sequence. Defaults to no slicing performed.
+        target_spans (tuple of [int, int] or sequence of tuples of [int, int], optional): Spans to slice for the
+            target sequence. Defaults to no slicing performed.
+    """
+
+    aggregator_name = "slices"
+    default_fn = None
+
+    @classmethod
+    def aggregate(
+        cls,
+        attr: "FeatureAttributionSequenceOutput",
+        source_spans: Optional[IndexSpan] = None,
+        target_spans: Optional[IndexSpan] = None,
+        **kwargs,
+    ):
+        """Spans can be:
+
+        1. A list of the form [pos_start, pos_end] including the contiguous positions of tokens that
+            are to be aggregated, if all values are integers and len(span) < len(original_seq)
+        2. A list of the form [(pos_start_0, pos_end_0), (pos_start_1, pos_end_1)], same as above but
+            for multiple contiguous spans.
+        """
+        source_spans = cls.format_spans(source_spans)
+        target_spans = cls.format_spans(target_spans)
+
+        if attr.source_attributions is None:
+            if source_spans is not None:
+                logger.warn(
+                    "Source spans are specified but no source scores are given for decoder-only models. "
+                    "Ignoring source spans and using target spans instead."
+                )
+            source_spans = [(s[0], min(s[1], attr.attr_pos_start)) for s in target_spans]
+
+        # Generated tokens are always included in the slices to preserve the output scores
+        is_gen_added = False
+        new_target_spans = []
+        if target_spans is not None:
+            for span in target_spans:
+                if span[1] > attr.attr_pos_start and is_gen_added:
+                    continue
+                elif span[1] > attr.attr_pos_start and not is_gen_added:
+                    new_target_spans.append((span[0], attr.attr_pos_end))
+                    is_gen_added = True
+                else:
+                    new_target_spans.append(span)
+        if not is_gen_added:
+            new_target_spans.append((attr.attr_pos_start, attr.attr_pos_end))
+        return super().aggregate(attr, source_spans=source_spans, target_spans=new_target_spans, **kwargs)
+
+    @staticmethod
+    def aggregate_source(attr: "FeatureAttributionSequenceOutput", source_spans: list[tuple[int, int]], **kwargs):
+        sliced_source = []
+        for span in source_spans:
+            sliced_source.extend(attr.source[span[0] : span[1]])
+        return sliced_source
+
+    @staticmethod
+    def aggregate_target(attr: "FeatureAttributionSequenceOutput", target_spans: list[tuple[int, int]], **kwargs):
+        sliced_target = []
+        for span in target_spans:
+            sliced_target.extend(attr.target[span[0] : span[1]])
+        return sliced_target
+
+    @staticmethod
+    def aggregate_source_attributions(attr: "FeatureAttributionSequenceOutput", source_spans, **kwargs):
+        if attr.source_attributions is None:
+            return attr.source_attributions
+        return torch.cat(
+            tuple(attr.source_attributions[span[0] : span[1], ...] for span in source_spans),
+            dim=0,
+        )
+
+    @staticmethod
+    def aggregate_target_attributions(attr: "FeatureAttributionSequenceOutput", target_spans, **kwargs):
+        if attr.target_attributions is None:
+            return attr.target_attributions
+        return torch.cat(
+            tuple(attr.target_attributions[span[0] : span[1], ...] for span in target_spans),
+            dim=0,
+        )
+
+    @staticmethod
+    def aggregate_step_scores(attr: "FeatureAttributionSequenceOutput", **kwargs):
+        return attr.step_scores
+
+    @classmethod
+    def aggregate_sequence_scores(
+        cls,
+        attr: "FeatureAttributionSequenceOutput",
+        source_spans,
+        target_spans,
+        **kwargs,
+    ):
+        if not attr.sequence_scores:
+            return attr.sequence_scores
+        out_dict = {}
+        for name, step_scores in attr.sequence_scores.items():
+            if name.startswith("decoder"):
+                out_dict[name] = torch.cat(
+                    tuple(step_scores[span[0] : span[1], ...] for span in target_spans),
+                    dim=0,
+                )
+            elif name.startswith("encoder"):
+                out_dict[name] = torch.cat(
+                    tuple(step_scores[span[0] : span[1], span[0] : span[1], ...] for span in source_spans),
+                    dim=0,
+                )
+            else:
+                out_dict[name] = torch.cat(
+                    tuple(step_scores[span[0] : span[1], ...] for span in source_spans),
+                    dim=0,
+                )
+        return out_dict
+
+    @staticmethod
+    def aggregate_attr_pos_start(attr: "FeatureAttributionSequenceOutput", target_spans, **kwargs):
+        if not target_spans:
+            return attr.attr_pos_start
+        tot_sliced_len = sum(min(s[1], attr.attr_pos_start) - s[0] for s in target_spans)
+        return tot_sliced_len
+
+    @staticmethod
+    def aggregate_attr_pos_end(attr: "FeatureAttributionSequenceOutput", **kwargs):
+        return attr.attr_pos_end
diff --git a/inseq/data/attribution.py b/inseq/data/attribution.py
index b83da1df..fec015f8 100644
--- a/inseq/data/attribution.py
+++ b/inseq/data/attribution.py
@@ -165,6 +165,16 @@ def __post_init__(self):
         if self.attr_pos_end is None or self.attr_pos_end > len(self.target):
             self.attr_pos_end = len(self.target)
 
+    def __getitem__(self, s: Union[slice, int]) -> "FeatureAttributionSequenceOutput":
+        source_spans = None if self.source_attributions is None else (s.start, s.stop)
+        target_spans = None if self.source_attributions is not None else (s.start, s.stop)
+        return self.aggregate("slices", source_spans=source_spans, target_spans=target_spans)
+
+    def __sub__(self, other: "FeatureAttributionSequenceOutput") -> "FeatureAttributionSequenceOutput":
+        if not isinstance(other, self.__class__):
+            raise ValueError(f"Cannot compare {type(other)} with {type(self)}")
+        return self.aggregate("pair", paired_attr=other, do_post_aggregation_checks=False)
+
     @staticmethod
     def get_remove_pad_fn(attr: "FeatureAttributionStepOutput", name: str) -> Callable:
         if attr.source_attributions is None or name.startswith("decoder"):
diff --git a/inseq/data/viz.py b/inseq/data/viz.py
index 5721dff1..28d7004a 100644
--- a/inseq/data/viz.py
+++ b/inseq/data/viz.py
@@ -209,12 +209,16 @@ def get_saliency_heatmap_html(
     uuid = "".join(random.choices(string.ascii_lowercase, k=20))
     out = saliency_heatmap_table_header
     # add top row containing target tokens
+    out += "<tr><th></th><th></th>"
+    for column_idx in range(len(column_labels)):
+        out += f"<th>{column_idx}</th>"
+    out += "</tr><tr><th></th><th></th>"
     for column_label in column_labels:
         out += f"<th>{sanitize_html(column_label)}</th>"
     out += "</tr>"
     if scores is not None:
         for row_index in range(scores.shape[0]):
-            out += f"<tr><th>{sanitize_html(row_labels[row_index])}</th>"
+            out += f"<tr><th>{row_index}</th><th>{sanitize_html(row_labels[row_index])}</th>"
             for col_index in range(scores.shape[1]):
                 score = ""
                 if not np.isnan(scores[row_index, col_index]):
@@ -223,7 +227,7 @@ def get_saliency_heatmap_html(
             out += "</tr>"
     if step_scores is not None:
         for step_score_name, step_score_values in step_scores.items():
-            out += f'<tr style="outline: thin solid"><th><b>{step_score_name}</b></th>'
+            out += f'<tr style="outline: thin solid"><th></th><th><b>{step_score_name}</b></th>'
             if isinstance(step_scores_threshold, float):
                 threshold = step_scores_threshold
             else:
@@ -254,20 +258,23 @@ def get_saliency_heatmap_rich(
     label: str = "",
     step_scores_threshold: Union[float, dict[str, float]] = 0.5,
 ):
-    columns = [Column(header="", justify="right", overflow="fold")]
-    for column_label in column_labels:
-        columns.append(Column(header=escape(column_label), justify="center", overflow="fold"))
+    columns = [
+        Column(header="", justify="right", overflow="fold"),
+        Column(header="", justify="right", overflow="fold"),
+    ]
+    for idx, column_label in enumerate(column_labels):
+        columns.append(Column(header=f"{idx}\n{escape(column_label)}", justify="center", overflow="fold"))
     table = Table(
         *columns,
         title=f"{label + ' ' if label else ''}Saliency Heatmap",
-        caption="x: Generated tokens, y: Attributed tokens",
+        caption="→ : Generated tokens, ↓ : Attributed tokens",
         padding=(0, 1, 0, 1),
         show_lines=False,
         box=box.HEAVY_HEAD,
     )
     if scores is not None:
         for row_index in range(scores.shape[0]):
-            row = [Text(escape(row_labels[row_index]), style="bold")]
+            row = [Text(f"{row_index}", style="bold"), Text(escape(row_labels[row_index]), style="bold")]
             for col_index in range(scores.shape[1]):
                 color = Color.from_rgb(*input_colors[row_index][col_index])
                 score = ""
@@ -282,7 +289,7 @@ def get_saliency_heatmap_rich(
             else:
                 threshold = step_scores_threshold.get(step_score_name, 0.5)
             style = lambda val, limit: "bold" if abs(val) >= limit and isinstance(val, float) else ""
-            score_row = [Text(escape(step_score_name), style="bold")]
+            score_row = [Text(""), Text(escape(step_score_name), style="bold")]
             for score in step_score_values:
                 curr_score = round(score.item(), 2) if isinstance(score, float) else score.item()
                 score_row.append(Text(f"{score:.2f}", justify="center", style=style(curr_score, threshold)))
diff --git a/inseq/utils/viz_utils.py b/inseq/utils/viz_utils.py
index 9de41d1a..69e4a94f 100644
--- a/inseq/utils/viz_utils.py
+++ b/inseq/utils/viz_utils.py
@@ -109,7 +109,6 @@ def get_colors(
 saliency_heatmap_table_header = """
 <table border="1" cellpadding="5" cellspacing="5"
     style="overflow-x:scroll;display:block;">
-    <tr><th></th>
 """
 
 saliency_heatmap_html = """
@@ -117,7 +116,7 @@ def get_colors(
     <div style="margin:5px;font-family:sans-serif;font-weight:bold;">
         <span style="font-size: 20px;">{label} Saliency Heatmap</span>
         <br>
-        x: Generated tokens, y: Attributed tokens
+        → : Generated tokens, ↓ : Attributed tokens
     </div>
     {content}
 </div>
diff --git a/requirements-dev.txt b/requirements-dev.txt
index d086fc10..4020d11f 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -1,6 +1,6 @@
 # This file was autogenerated by uv via the following command:
 #    uv pip compile --all-extras pyproject.toml -o requirements-dev.txt
-aiohttp==3.9.3
+aiohttp==3.9.5
     # via
     #   datasets
     #   fsspec
@@ -19,10 +19,12 @@ authlib==1.3.0
 babel==2.14.0
     # via sphinx
 bandit==1.7.7
+    # via inseq (pyproject.toml)
 beautifulsoup4==4.12.3
     # via furo
 captum==0.7.0
-certifi==2024.2.2
+    # via inseq (pyproject.toml)
+certifi==2024.6.2
     # via requests
 cffi==1.16.0
     # via cryptography
@@ -49,6 +51,7 @@ cryptography==42.0.5
 cycler==0.12.1
     # via matplotlib
 datasets==2.17.0
+    # via inseq (pyproject.toml)
 debugpy==1.8.1
     # via ipykernel
 decorator==5.1.1
@@ -90,6 +93,7 @@ fsspec==2023.10.0
     #   huggingface-hub
     #   torch
 furo==2024.1.29
+    # via inseq (pyproject.toml)
 gitdb==4.0.11
     # via gitpython
 gitpython==3.1.41
@@ -110,21 +114,25 @@ imagesize==1.4.1
 iniconfig==2.0.0
     # via pytest
 ipykernel==6.29.2
+    # via inseq (pyproject.toml)
 ipython==8.18.1
     # via
     #   ipykernel
     #   ipywidgets
 ipywidgets==8.1.2
+    # via inseq (pyproject.toml)
 jaxtyping==0.2.25
+    # via inseq (pyproject.toml)
 jedi==0.19.1
     # via ipython
-jinja2==3.1.3
+jinja2==3.1.4
     # via
     #   safety
     #   sphinx
     #   torch
 joblib==1.3.2
     # via
+    #   inseq (pyproject.toml)
     #   nltk
     #   scikit-learn
 jupyter-client==8.6.0
@@ -144,7 +152,9 @@ markupsafe==2.1.5
 marshmallow==3.20.2
     # via safety
 matplotlib==3.8.2
-    # via captum
+    # via
+    #   inseq (pyproject.toml)
+    #   captum
 matplotlib-inline==0.1.6
     # via
     #   ipykernel
@@ -164,10 +174,12 @@ nest-asyncio==1.6.0
 networkx==3.2.1
     # via torch
 nltk==3.8.1
+    # via inseq (pyproject.toml)
 nodeenv==1.8.0
     # via pre-commit
 numpy==1.26.4
     # via
+    #   inseq (pyproject.toml)
     #   captum
     #   contourpy
     #   datasets
@@ -199,7 +211,7 @@ pbr==6.0.0
     # via stevedore
 pexpect==4.9.0
     # via ipython
-pillow==10.3.0
+pillow==10.4.0
     # via matplotlib
 platformdirs==4.2.0
     # via
@@ -208,10 +220,13 @@ platformdirs==4.2.0
 pluggy==1.4.0
     # via pytest
 pre-commit==3.6.1
+    # via inseq (pyproject.toml)
 prompt-toolkit==3.0.43
     # via ipython
 protobuf==4.25.2
-    # via transformers
+    # via
+    #   inseq (pyproject.toml)
+    #   transformers
 psutil==5.9.8
     # via ipykernel
 ptyprocess==0.7.0
@@ -229,6 +244,7 @@ pydantic==1.10.14
     #   safety
     #   safety-schemas
 pydoclint==0.4.0
+    # via inseq (pyproject.toml)
 pygments==2.17.2
     # via
     #   furo
@@ -239,10 +255,13 @@ pyparsing==3.1.1
     # via matplotlib
 pytest==8.0.0
     # via
+    #   inseq (pyproject.toml)
     #   pytest-cov
     #   pytest-xdist
 pytest-cov==4.1.0
+    # via inseq (pyproject.toml)
 pytest-xdist==3.5.0
+    # via inseq (pyproject.toml)
 python-dateutil==2.8.2
     # via
     #   jupyter-client
@@ -265,7 +284,7 @@ regex==2023.12.25
     # via
     #   nltk
     #   transformers
-requests==2.31.0
+requests==2.32.3
     # via
     #   datasets
     #   fsspec
@@ -275,6 +294,7 @@ requests==2.31.0
     #   transformers
 rich==13.7.0
     # via
+    #   inseq (pyproject.toml)
     #   bandit
     #   safety
 ruamel-yaml==0.18.6
@@ -284,12 +304,15 @@ ruamel-yaml==0.18.6
 ruamel-yaml-clib==0.2.8
     # via ruamel-yaml
 ruff==0.2.1
+    # via inseq (pyproject.toml)
 safetensors==0.4.2
     # via transformers
 safety==3.1.0
+    # via inseq (pyproject.toml)
 safety-schemas==0.0.2
     # via safety
 scikit-learn==1.4.0
+    # via inseq (pyproject.toml)
 scipy==1.12.0
     # via scikit-learn
 sentencepiece==0.1.99
@@ -310,6 +333,7 @@ soupsieve==2.5
     # via beautifulsoup4
 sphinx==7.2.6
     # via
+    #   inseq (pyproject.toml)
     #   furo
     #   sphinx-basic-ng
     #   sphinx-copybutton
@@ -320,8 +344,11 @@ sphinx==7.2.6
 sphinx-basic-ng==1.0.0b2
     # via furo
 sphinx-copybutton==0.5.2
+    # via inseq (pyproject.toml)
 sphinx-design==0.5.0
+    # via inseq (pyproject.toml)
 sphinx-gitstamp==0.4.0
+    # via inseq (pyproject.toml)
 sphinxcontrib-applehelp==1.0.8
     # via sphinx
 sphinxcontrib-devhelp==1.0.6
@@ -335,7 +362,9 @@ sphinxcontrib-qthelp==1.0.7
 sphinxcontrib-serializinghtml==1.1.10
     # via sphinx
 sphinxemoji==0.3.1
+    # via inseq (pyproject.toml)
 sphinxext-opengraph==0.9.1
+    # via inseq (pyproject.toml)
 stack-data==0.6.3
     # via ipython
 stevedore==5.1.0
@@ -347,13 +376,16 @@ threadpoolctl==3.2.0
 tokenizers==0.15.2
     # via transformers
 torch==2.2.0
-    # via captum
+    # via
+    #   inseq (pyproject.toml)
+    #   captum
 tornado==6.4
     # via
     #   ipykernel
     #   jupyter-client
-tqdm==4.66.2
+tqdm==4.66.4
     # via
+    #   inseq (pyproject.toml)
     #   captum
     #   datasets
     #   huggingface-hub
@@ -369,8 +401,11 @@ traitlets==5.14.1
     #   jupyter-core
     #   matplotlib-inline
 transformers==4.38.1
+    # via inseq (pyproject.toml)
 typeguard==2.13.3
-    # via jaxtyping
+    # via
+    #   inseq (pyproject.toml)
+    #   jaxtyping
 typer==0.9.0
     # via safety
 typing-extensions==4.9.0
@@ -384,7 +419,7 @@ typing-extensions==4.9.0
     #   typer
 tzdata==2024.1
     # via pandas
-urllib3==2.2.0
+urllib3==2.2.2
     # via
     #   requests
     #   safety
diff --git a/requirements.txt b/requirements.txt
index 05e5b4c7..9c021743 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,7 +1,8 @@
 # This file was autogenerated by uv via the following command:
 #    uv pip compile pyproject.toml -o requirements.txt
 captum==0.7.0
-certifi==2024.2.2
+    # via inseq (pyproject.toml)
+certifi==2024.6.2
     # via requests
 charset-normalizer==3.3.2
     # via requests
@@ -27,7 +28,8 @@ huggingface-hub==0.20.3
 idna==3.7
     # via requests
 jaxtyping==0.2.25
-jinja2==3.1.3
+    # via inseq (pyproject.toml)
+jinja2==3.1.4
     # via torch
 kiwisolver==1.4.5
     # via matplotlib
@@ -36,7 +38,9 @@ markdown-it-py==3.0.0
 markupsafe==2.1.5
     # via jinja2
 matplotlib==3.8.2
-    # via captum
+    # via
+    #   inseq (pyproject.toml)
+    #   captum
 mdurl==0.1.2
     # via markdown-it-py
 mpmath==1.3.0
@@ -45,6 +49,7 @@ networkx==3.2.1
     # via torch
 numpy==1.26.4
     # via
+    #   inseq (pyproject.toml)
     #   captum
     #   contourpy
     #   jaxtyping
@@ -55,10 +60,12 @@ packaging==23.2
     #   huggingface-hub
     #   matplotlib
     #   transformers
-pillow==10.3.0
+pillow==10.4.0
     # via matplotlib
 protobuf==4.25.2
-    # via transformers
+    # via
+    #   inseq (pyproject.toml)
+    #   transformers
 pygments==2.17.2
     # via rich
 pyparsing==3.1.1
@@ -71,11 +78,12 @@ pyyaml==6.0.1
     #   transformers
 regex==2023.12.25
     # via transformers
-requests==2.31.0
+requests==2.32.3
     # via
     #   huggingface-hub
     #   transformers
 rich==13.7.0
+    # via inseq (pyproject.toml)
 safetensors==0.4.2
     # via transformers
 sentencepiece==0.1.99
@@ -87,19 +95,25 @@ sympy==1.12
 tokenizers==0.15.2
     # via transformers
 torch==2.2.0
-    # via captum
-tqdm==4.66.2
     # via
+    #   inseq (pyproject.toml)
+    #   captum
+tqdm==4.66.4
+    # via
+    #   inseq (pyproject.toml)
     #   captum
     #   huggingface-hub
     #   transformers
 transformers==4.38.1
+    # via inseq (pyproject.toml)
 typeguard==2.13.3
-    # via jaxtyping
+    # via
+    #   inseq (pyproject.toml)
+    #   jaxtyping
 typing-extensions==4.9.0
     # via
     #   huggingface-hub
     #   jaxtyping
     #   torch
-urllib3==2.2.0
+urllib3==2.2.2
     # via requests
diff --git a/tests/data/test_aggregator.py b/tests/data/test_aggregator.py
index f7e7c3e5..14360c7f 100644
--- a/tests/data/test_aggregator.py
+++ b/tests/data/test_aggregator.py
@@ -5,6 +5,7 @@
 from pytest import fixture
 
 import inseq
+from inseq.data import FeatureAttributionSequenceOutput
 from inseq.data.aggregator import (
     AggregatorPipeline,
     ContiguousSpanAggregator,
@@ -149,6 +150,10 @@ def test_pair_aggregator(saliency_mt_model: HuggingfaceEncoderDecoderModel):
     diff_seqattr_other = orig_seqattr_other.aggregate("pair", paired_attr=alt_seqattr_other)
     assert torch.allclose(diff_seqattr_other.source_attributions, diff_seqattr.source_attributions)
 
+    # Aggregate with __sub__
+    diff_seqattr_sub = orig_seqattr - alt_seqattr
+    assert diff_seqattr_other == diff_seqattr_sub
+
 
 def test_named_aggregate_fn_aggregation(saliency_mt_model: HuggingfaceEncoderDecoderModel):
     out = saliency_mt_model.attribute(
@@ -192,3 +197,29 @@ def test_named_aggregate_fn_aggregation(saliency_mt_model: HuggingfaceEncoderDec
         aggregator=["scores", "scores", "subwords"], aggregate_fn=["mean", "mean", None]
     )
     assert out_allmean_subwords == out_allmean_subwords_expanded
+
+
+def test_slice_aggregator_decoder_only(saliency_gpt_model: HuggingfaceDecoderOnlyModel):
+    out = saliency_gpt_model.attribute(
+        EXAMPLES["source_summary"], EXAMPLES["source_summary"] + EXAMPLES["gen_summary"], show_progress=False
+    )[0]
+    out_sliced: FeatureAttributionSequenceOutput = out.aggregate("slices", target_spans=(14, 75))
+    assert [t.token for t in out_sliced.source] == EXAMPLES["source_summary_tokens"]
+    assert [t.token for t in out_sliced.target] == EXAMPLES["source_summary_tokens"] + EXAMPLES["gen_summary_tokens"]
+
+    # Slice with __getitem__
+    out_sliced_getitem = out[14:75]
+    assert out_sliced == out_sliced_getitem
+
+
+def test_slice_aggregator_encoder_decoder(saliency_mt_model: HuggingfaceEncoderDecoderModel):
+    out = saliency_mt_model.attribute(
+        EXAMPLES["source"], EXAMPLES["target"], show_progress=False, attribute_target=True
+    )[0]
+    out_sliced: FeatureAttributionSequenceOutput = out.aggregate("slices", source_spans=(1, 4))
+    assert [t.token for t in out_sliced.source] == EXAMPLES["source_subwords"][1:4]
+    assert [t.token for t in out_sliced.target] == EXAMPLES["target_subwords"][1:]
+
+    # Slice with __getitem__
+    out_sliced_getitem = out[1:4]
+    assert out_sliced == out_sliced_getitem
diff --git a/tests/fixtures/aggregator.json b/tests/fixtures/aggregator.json
index 53123526..51d6b20d 100644
--- a/tests/fixtures/aggregator.json
+++ b/tests/fixtures/aggregator.json
@@ -93,5 +93,90 @@
         "\u2581models",
         ".",
         "</s>"
+    ],
+    "source_summary": "Instruction: Summarize this article.\nInput_text: In a quiet village nestled between rolling hills, an ancient tree whispered secrets to those who listened. One night, a curious child named Elara leaned close and heard tales of hidden treasures beneath the roots. As dawn broke, she unearthed a shimmering box, unlocking a forgotten world of wonder and magic.\nSummary:",
+    "gen_summary": " Elara discovers a shimmering box under an ancient tree, unlocking a world of magic.",
+    "source_summary_tokens": [
+        "\u0120In",
+        "\u0120a",
+        "\u0120quiet",
+        "\u0120village",
+        "\u0120nest",
+        "led",
+        "\u0120between",
+        "\u0120rolling",
+        "\u0120hills",
+        ",",
+        "\u0120an",
+        "\u0120ancient",
+        "\u0120tree",
+        "\u0120whispered",
+        "\u0120secrets",
+        "\u0120to",
+        "\u0120those",
+        "\u0120who",
+        "\u0120listened",
+        ".",
+        "\u0120One",
+        "\u0120night",
+        ",",
+        "\u0120a",
+        "\u0120curious",
+        "\u0120child",
+        "\u0120named",
+        "\u0120El",
+        "ara",
+        "\u0120leaned",
+        "\u0120close",
+        "\u0120and",
+        "\u0120heard",
+        "\u0120tales",
+        "\u0120of",
+        "\u0120hidden",
+        "\u0120treasures",
+        "\u0120beneath",
+        "\u0120the",
+        "\u0120roots",
+        ".",
+        "\u0120As",
+        "\u0120dawn",
+        "\u0120broke",
+        ",",
+        "\u0120she",
+        "\u0120unearthed",
+        "\u0120a",
+        "\u0120shimmer",
+        "ing",
+        "\u0120box",
+        ",",
+        "\u0120unlocking",
+        "\u0120a",
+        "\u0120forgotten",
+        "\u0120world",
+        "\u0120of",
+        "\u0120wonder",
+        "\u0120and",
+        "\u0120magic",
+        "."
+    ],
+    "gen_summary_tokens": [
+        "\u0120El",
+        "ara",
+        "\u0120discovers",
+        "\u0120a",
+        "\u0120shimmer",
+        "ing",
+        "\u0120box",
+        "\u0120under",
+        "\u0120an",
+        "\u0120ancient",
+        "\u0120tree",
+        ",",
+        "\u0120unlocking",
+        "\u0120a",
+        "\u0120world",
+        "\u0120of",
+        "\u0120magic",
+        "."
     ]
 }