diff --git a/app/graphql/resolvers/ci/all_jobs_resolver.rb b/app/graphql/resolvers/ci/all_jobs_resolver.rb
index 8e9a1deb5419fd2a9f7f994cb0adde7bdfa3579d..54dd435d617d8f82c0f10140103fd95bb387c870 100644
--- a/app/graphql/resolvers/ci/all_jobs_resolver.rb
+++ b/app/graphql/resolvers/ci/all_jobs_resolver.rb
@@ -39,9 +39,18 @@ def preloads
           browse_artifacts_path: [{ project: { namespace: [:route] } }],
           play_path: [{ project: { namespace: [:route] } }],
           web_path: [{ project: { namespace: [:route] } }],
-          tags: [:tags]
+          tags: [:tags],
+          trace: [{ project: [:namespace] }, :job_artifacts_trace]
         }
       end
+
+      def nested_preloads
+        super.merge({
+          trace: {
+            html_summary: [:trace_chunks]
+          }
+        })
+      end
     end
   end
 end
diff --git a/app/graphql/resolvers/ci/runner_jobs_resolver.rb b/app/graphql/resolvers/ci/runner_jobs_resolver.rb
index 39908d8fd11332bb6c07a6585e71a281da3d689a..c0a5057cddd070627fc726eb2000267c6066b647 100644
--- a/app/graphql/resolvers/ci/runner_jobs_resolver.rb
+++ b/app/graphql/resolvers/ci/runner_jobs_resolver.rb
@@ -44,9 +44,18 @@ def preloads
           play_path: [{ project: { namespace: [:route] } }],
           web_path: [{ project: { namespace: [:route] } }],
           short_sha: [:pipeline],
-          tags: [:tags]
+          tags: [:tags],
+          trace: [{ project: [:namespace] }, :job_artifacts_trace]
         }
       end
+
+      def nested_preloads
+        super.merge({
+          trace: {
+            html_summary: [:trace_chunks]
+          }
+        })
+      end
     end
   end
 end
diff --git a/app/graphql/types/ci/job_trace_type.rb b/app/graphql/types/ci/job_trace_type.rb
index a68e26106b8687938ac247b1f1a707a1236e7797..b959d37f3272949ff14d7d61709f4cc01e199513 100644
--- a/app/graphql/types/ci/job_trace_type.rb
+++ b/app/graphql/types/ci/job_trace_type.rb
@@ -7,11 +7,15 @@ class JobTraceType < BaseObject
       graphql_name 'CiJobTrace'
 
       field :html_summary, GraphQL::Types::String, null: false,
-        alpha: { milestone: '15.11' }, # As we want the option to change from 10 if needed
-        description: "HTML summary containing the last 10 lines of the trace."
+        alpha: { milestone: '15.11' },
+        description: 'HTML summary that contains the tail lines of the trace.' do
+        argument :last_lines, Integer,
+          required: false, default_value: 10,
+          description: 'Number of tail lines to return, up to a maximum of 100 lines.'
+      end
 
-      def html_summary
-        object.html(last_lines: 10).html_safe
+      def html_summary(last_lines:)
+        object.html(last_lines: last_lines.clamp(1, 100)).html_safe
       end
     end
   end
diff --git a/doc/api/graphql/reference/index.md b/doc/api/graphql/reference/index.md
index 49bb9fdbefd021e4ddb9ce434271edcc133c0b59..a1fc29747439afe215891912941421fe4b35be4a 100644
--- a/doc/api/graphql/reference/index.md
+++ b/doc/api/graphql/reference/index.md
@@ -13866,11 +13866,23 @@ CI/CD variables for a GitLab instance.
 
 ### `CiJobTrace`
 
-#### Fields
+#### Fields with arguments
+
+##### `CiJobTrace.htmlSummary`
+
+HTML summary that contains the tail lines of the trace.
+
+WARNING:
+**Introduced** in 15.11.
+This feature is an Experiment. It can be changed or removed at any time.
+
+Returns [`String!`](#string).
+
+###### Arguments
 
 | Name | Type | Description |
 | ---- | ---- | ----------- |
-| <a id="cijobtracehtmlsummary"></a>`htmlSummary` **{warning-solid}** | [`String!`](#string) | **Introduced** in 15.11. This feature is an Experiment. It can be changed or removed at any time. HTML summary containing the last 10 lines of the trace. |
+| <a id="cijobtracehtmlsummarylastlines"></a>`lastLines` | [`Int`](#int) | Number of tail lines to return, up to a maximum of 100 lines. |
 
 ### `CiJobsDurationStatistics`
 
diff --git a/spec/graphql/types/ci/job_trace_type_spec.rb b/spec/graphql/types/ci/job_trace_type_spec.rb
index 71803aa9ece3f96ada5ff9cabaec2c834abba641..5f4f3097ace7920377359af59b3da540d04c3110 100644
--- a/spec/graphql/types/ci/job_trace_type_spec.rb
+++ b/spec/graphql/types/ci/job_trace_type_spec.rb
@@ -13,15 +13,83 @@
     expect(described_class).to have_graphql_fields(*expected_fields)
   end
 
-  it 'shows the correct trace contents' do
-    job.trace.set('BUILD TRACE')
+  describe 'htmlSummary' do
+    subject(:resolved_field) { resolve_field(:html_summary, job.trace, args: args) }
 
-    expect_next_instance_of(Gitlab::Ci::Trace) do |trace|
-      expect(trace).to receive(:html).with(last_lines: 10).and_call_original
+    context 'when trace contains few lines' do
+      before do
+        job.trace.set('BUILD TRACE')
+      end
+
+      context 'when last_lines is set to 10' do
+        let(:args) { { last_lines: 10 } }
+
+        it 'shows the correct trace contents' do
+          expect_next_instance_of(Gitlab::Ci::Trace) do |trace|
+            expect(trace).to receive(:html).with(last_lines: 10).and_call_original
+          end
+
+          is_expected.to eq('<span>BUILD TRACE</span>')
+        end
+      end
     end
 
-    resolved_field = resolve_field(:html_summary, job.trace)
+    context 'when trace contains many lines' do
+      before do
+        job.trace.set((1..200).map { |i| "Line #{i}" }.join("\n"))
+      end
+
+      def expected_html_trace_contents(line_count)
+        "<span>#{((200 - (line_count - 1))..200).map { |i| "Line #{i}" }.join('<br/>')}</span>"
+      end
+
+      context 'when last_lines is not set' do
+        let(:args) { {} }
+
+        it 'shows the last 10 lines of trace contents' do
+          expect_next_instance_of(Gitlab::Ci::Trace) do |trace|
+            expect(trace).to receive(:html).with(last_lines: 10).and_call_original
+          end
+
+          is_expected.to eq expected_html_trace_contents(10)
+        end
+      end
+
+      context 'when last_lines is set to a negative number' do
+        let(:args) { { last_lines: -10 } }
 
-    expect(resolved_field).to eq("<span>BUILD TRACE</span>")
+        it 'shows the last line of trace contents' do
+          expect_next_instance_of(Gitlab::Ci::Trace) do |trace|
+            expect(trace).to receive(:html).with(last_lines: 1).and_call_original
+          end
+
+          is_expected.to eq expected_html_trace_contents(1)
+        end
+      end
+
+      context 'when last_lines is set to 10' do
+        let(:args) { { last_lines: 10 } }
+
+        it 'shows the correct trace contents' do
+          expect_next_instance_of(Gitlab::Ci::Trace) do |trace|
+            expect(trace).to receive(:html).with(last_lines: 10).and_call_original
+          end
+
+          is_expected.to eq expected_html_trace_contents(10)
+        end
+      end
+
+      context 'when last_lines is set to 150' do
+        let(:args) { { last_lines: 150 } }
+
+        it 'shows the last 100 lines of trace contents' do
+          expect_next_instance_of(Gitlab::Ci::Trace) do |trace|
+            expect(trace).to receive(:html).with(last_lines: 100).and_call_original
+          end
+
+          is_expected.to eq expected_html_trace_contents(100)
+        end
+      end
+    end
   end
 end