diff --git a/Cargo.lock b/Cargo.lock
index 1bc4170..1d85ee2 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -11,6 +11,15 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "android_system_properties"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "819e7219dbd41043ac279b19830f2efc897156490d7fd6ea916720117ee66311"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "anstream"
 version = "1.0.0"
@@ -98,6 +107,12 @@ version = "1.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1505bd5d3d116872e7271a6d4e16d81d0c8570876c8de68093a09ac269d8aac0"
 
+[[package]]
+name = "autocfg"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c08606f8c3cbf4ce6ec8e28fb0014a2c086708fe954eaa885384a6165172e7e8"
+
 [[package]]
 name = "base64"
 version = "0.22.1"
@@ -155,6 +170,20 @@ version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "613afe47fcd5fac7ccf1db93babcb082c5994d996f20b8b159f2ad1658eb5724"
 
+[[package]]
+name = "chrono"
+version = "0.4.44"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c673075a2e0e5f4a1dde27ce9dee1ea4558c7ffe648f576438a20ca1d2acc4b0"
+dependencies = [
+ "iana-time-zone",
+ "js-sys",
+ "num-traits",
+ "serde",
+ "wasm-bindgen",
+ "windows-link",
+]
+
 [[package]]
 name = "clap"
 version = "4.6.0"
@@ -210,6 +239,12 @@ dependencies = [
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "core-foundation-sys"
+version = "0.8.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "773648b94d0e5d620f64f280777445740e61fe701025087ec8b57f45c791888b"
+
 [[package]]
 name = "difflib"
 version = "0.4.0"
@@ -371,6 +406,7 @@ version = "0.1.0"
 dependencies = [
  "anyhow",
  "assert_cmd",
+ "chrono",
  "clap",
  "mockito",
  "reqwest",
@@ -527,6 +563,30 @@ dependencies = [
  "tracing",
 ]
 
+[[package]]
+name = "iana-time-zone"
+version = "0.1.65"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e31bc9ad994ba00e440a8aa5c9ef0ec67d5cb5e5cb0cc7f8b744a35b389cc470"
+dependencies = [
+ "android_system_properties",
+ "core-foundation-sys",
+ "iana-time-zone-haiku",
+ "js-sys",
+ "log",
+ "wasm-bindgen",
+ "windows-core",
+]
+
+[[package]]
+name = "iana-time-zone-haiku"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f31827a206f56af32e590ba56d5d2d085f558508192593743f16b2306495269f"
+dependencies = [
+ "cc",
+]
+
 [[package]]
 name = "icu_collections"
 version = "2.2.0"
@@ -775,6 +835,15 @@ dependencies = [
  "tokio",
 ]
 
+[[package]]
+name = "num-traits"
+version = "0.2.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "071dfc062690e90b734c0b2273ce72ad0ffa95f0c74596bc250dcfd960262841"
+dependencies = [
+ "autocfg",
+]
+
 [[package]]
 name = "once_cell"
 version = "1.21.4"
@@ -1693,12 +1762,65 @@ dependencies = [
  "rustls-pki-types",
 ]
 
+[[package]]
+name = "windows-core"
+version = "0.62.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b8e83a14d34d0623b51dce9581199302a221863196a1dde71a7663a4c2be9deb"
+dependencies = [
+ "windows-implement",
+ "windows-interface",
+ "windows-link",
+ "windows-result",
+ "windows-strings",
+]
+
+[[package]]
+name = "windows-implement"
+version = "0.60.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "053e2e040ab57b9dc951b72c264860db7eb3b0200ba345b4e4c3b14f67855ddf"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "windows-interface"
+version = "0.59.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3f316c4a2570ba26bbec722032c4099d8c8bc095efccdc15688708623367e358"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "windows-link"
 version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f0805222e57f7521d6a62e36fa9163bc891acd422f971defe97d64e70d0a4fe5"
 
+[[package]]
+name = "windows-result"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7781fa89eaf60850ac3d2da7af8e5242a5ea78d1a11c49bf2910bb5a73853eb5"
+dependencies = [
+ "windows-link",
+]
+
+[[package]]
+name = "windows-strings"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7837d08f69c77cf6b07689544538e017c1bfcf57e34b4c0ff58e6c2cd3b37091"
+dependencies = [
+ "windows-link",
+]
+
 [[package]]
 name = "windows-sys"
 version = "0.52.0"
diff --git a/Cargo.toml b/Cargo.toml
index d84a27e..a099749 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -6,6 +6,7 @@ edition = "2024"
 [dependencies]
 anyhow = "1.0"
 clap = { version = "4.5", features = ["derive"] }
+chrono = { version = "0.4", features = ["serde"] }
 reqwest = { version = "0.12", default-features = false, features = ["blocking", "json", "rustls-tls"] }
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
diff --git a/src/lib.rs b/src/lib.rs
index 42d71f2..e179de8 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -6,6 +6,7 @@ pub mod cli;
 pub mod error;
 pub mod gitea;
 pub mod model;
+pub mod normalize;
 pub mod output;
 pub mod render;
 
diff --git a/src/normalize.rs b/src/normalize.rs
new file mode 100644
index 0000000..f6802fd
--- /dev/null
+++ b/src/normalize.rs
@@ -0,0 +1,251 @@
+use std::collections::BTreeMap;
+use std::convert::TryFrom;
+
+use chrono::{DateTime, FixedOffset};
+
+use crate::gitea::dto::{ChangedFileDto, CommitDto, PullBundleDto, ReviewCommentDto, ReviewDto};
+use crate::model::{
+    CommentItem, CommentThread, CommitItem, DiffStat, FileStat, PrMeta, PrReviewDocument,
+    ReviewItem,
+};
+
+pub fn normalize_bundle(repo: &str, bundle: PullBundleDto) -> PrReviewDocument {
+    let PullBundleDto {
+        pull,
+        reviews,
+        comments,
+        commits,
+        files,
+    } = bundle;
+
+    let mut threads = normalize_threads(comments);
+    threads.sort_by(|a, b| {
+        comment_item_sort_key(&a.root_comment).cmp(&comment_item_sort_key(&b.root_comment))
+    });
+
+    let commits = normalize_commits(commits);
+    let reviews = normalize_reviews(reviews);
+    let diff_stat = normalize_diff_stat(&pull, files);
+
+    PrReviewDocument {
+        meta: PrMeta {
+            repo: repo.to_string(),
+            pr_index: pull.number,
+            title: pull.title,
+            state: pull.state,
+            author: pull.user.login,
+            base_branch: pull.base.ref_name,
+            head_branch: pull.head.ref_name,
+            created_at: pull.created_at,
+            updated_at: pull.updated_at,
+            merged_at: pull.merged_at,
+        },
+        commits,
+        diff_stat,
+        reviews,
+        threads,
+    }
+}
+
+fn normalize_threads(comments: Vec<ReviewCommentDto>) -> Vec<CommentThread> {
+    let mut grouped: BTreeMap<String, Vec<ReviewCommentDto>> = BTreeMap::new();
+
+    for comment in comments {
+        let key = thread_key(&comment);
+        grouped.entry(key).or_default().push(comment);
+    }
+
+    grouped
+        .into_iter()
+        .map(|(thread_id, mut group)| {
+            group.sort_by(|a, b| comment_sort_key(a).cmp(&comment_sort_key(b)));
+
+            let root = group.remove(0);
+            let file_path = root
+                .path
+                .clone()
+                .or_else(|| group.iter().find_map(|comment| comment.path.clone()));
+            let line = root
+                .line
+                .or_else(|| group.iter().find_map(|comment| comment.line));
+
+            CommentThread {
+                thread_id,
+                file_path,
+                line,
+                root_comment: to_comment_item(root),
+                replies: group.into_iter().map(to_comment_item).collect(),
+            }
+        })
+        .collect()
+}
+
+fn thread_key(comment: &ReviewCommentDto) -> String {
+    match comment.pull_request_review_id {
+        Some(review_id) => format!(
+            "review-{review_id}-{path}-{line}-{position}-{commit}",
+            path = comment.path.as_deref().unwrap_or(""),
+            line = comment
+                .line
+                .map(|value| value.to_string())
+                .unwrap_or_default(),
+            position = comment
+                .original_position
+                .or(comment.position)
+                .map(|value| value.to_string())
+                .unwrap_or_default(),
+            commit = comment
+                .original_commit_id
+                .as_deref()
+                .or(comment.commit_id.as_deref())
+                .unwrap_or("")
+        ),
+        None => format!("comment-{}", comment.id),
+    }
+}
+
+fn normalize_commits(commits: Vec<CommitDto>) -> Vec<CommitItem> {
+    let mut commits = commits;
+    commits.sort_by(|a, b| {
+        commit_sort_key(a)
+            .cmp(&commit_sort_key(b))
+            .then_with(|| a.sha.cmp(&b.sha))
+    });
+
+    commits.into_iter().map(to_commit_item).collect()
+}
+
+fn normalize_reviews(reviews: Vec<ReviewDto>) -> Vec<ReviewItem> {
+    let mut reviews = reviews;
+    reviews.sort_by(|a, b| {
+        review_sort_key(a)
+            .cmp(&review_sort_key(b))
+            .then_with(|| a.id.cmp(&b.id))
+    });
+
+    reviews
+        .into_iter()
+        .map(|review| ReviewItem {
+            id: review.id,
+            state: review.state,
+            reviewer: review.user.login,
+            submitted_at: review.submitted_at,
+        })
+        .collect()
+}
+
+fn normalize_diff_stat(pull: &crate::gitea::dto::PullDto, files: Vec<ChangedFileDto>) -> DiffStat {
+    let file_stats: Vec<FileStat> = files
+        .into_iter()
+        .map(|file| FileStat {
+            path: file.filename,
+            additions: file.additions,
+            deletions: file.deletions,
+        })
+        .collect();
+
+    let files_changed = if file_stats.is_empty() {
+        pull.changed_files
+            .and_then(|value| usize::try_from(value).ok())
+            .unwrap_or_default()
+    } else {
+        file_stats.len()
+    };
+
+    let additions: i64 = if file_stats.is_empty() {
+        pull.additions.unwrap_or_default()
+    } else {
+        file_stats.iter().map(|file| file.additions).sum()
+    };
+    let deletions: i64 = if file_stats.is_empty() {
+        pull.deletions.unwrap_or_default()
+    } else {
+        file_stats.iter().map(|file| file.deletions).sum()
+    };
+
+    DiffStat {
+        files_changed,
+        additions,
+        deletions,
+        files: file_stats,
+    }
+}
+
+fn to_commit_item(commit: CommitDto) -> CommitItem {
+    let title = commit
+        .commit
+        .message
+        .lines()
+        .next()
+        .unwrap_or_default()
+        .to_string();
+    let short_sha = commit.sha.chars().take(7).collect::<String>();
+    let author = commit
+        .commit
+        .author
+        .as_ref()
+        .map(|author| author.name.clone())
+        .unwrap_or_default();
+    let date = commit
+        .commit
+        .author
+        .as_ref()
+        .map(|author| author.date.clone())
+        .unwrap_or_default();
+
+    CommitItem {
+        sha: commit.sha,
+        short_sha,
+        title,
+        author,
+        date,
+    }
+}
+
+fn to_comment_item(comment: ReviewCommentDto) -> CommentItem {
+    CommentItem {
+        id: comment.id,
+        user: comment.user.login,
+        created_at: comment.created_at,
+        body: comment.body,
+    }
+}
+
+fn review_sort_key(review: &ReviewDto) -> (i64, i64) {
+    (timestamp_millis(review.submitted_at.as_deref()), review.id)
+}
+
+fn commit_sort_key(commit: &CommitDto) -> (i64, String) {
+    (
+        timestamp_millis(Some(
+            commit
+                .commit
+                .author
+                .as_ref()
+                .map(|author| author.date.as_str())
+                .unwrap_or_default(),
+        )),
+        commit.sha.clone(),
+    )
+}
+
+fn comment_sort_key(comment: &ReviewCommentDto) -> (i64, i64) {
+    (
+        timestamp_millis(Some(comment.created_at.as_str())),
+        comment.id,
+    )
+}
+
+fn comment_item_sort_key(comment: &CommentItem) -> (i64, i64) {
+    (
+        timestamp_millis(Some(comment.created_at.as_str())),
+        comment.id,
+    )
+}
+
+fn timestamp_millis(input: Option<&str>) -> i64 {
+    input
+        .and_then(|value| DateTime::parse_from_rfc3339(value).ok())
+        .map(|dt: DateTime<FixedOffset>| dt.timestamp_millis())
+        .unwrap_or(0)
+}
diff --git a/tests/normalize_tests.rs b/tests/normalize_tests.rs
new file mode 100644
index 0000000..af3e4b7
--- /dev/null
+++ b/tests/normalize_tests.rs
@@ -0,0 +1,172 @@
+use gitea_pr_review::gitea::dto::*;
+use gitea_pr_review::normalize::normalize_bundle;
+
+#[test]
+fn normalize_groups_replies_and_sorts_threads_by_time() {
+    let bundle = PullBundleDto {
+        pull: PullDto {
+            number: 42,
+            title: "Fix parser".into(),
+            state: "open".into(),
+            body: Some("desc".into()),
+            user: UserDto {
+                login: "alice".into(),
+            },
+            base: PullBranchDto {
+                ref_name: "main".into(),
+            },
+            head: PullBranchDto {
+                ref_name: "feature/x".into(),
+            },
+            created_at: "2026-04-08T10:00:00Z".into(),
+            updated_at: "2026-04-08T11:00:00Z".into(),
+            merged_at: None,
+            additions: Some(99),
+            deletions: Some(33),
+            changed_files: Some(7),
+        },
+        reviews: vec![
+            ReviewDto {
+                id: 8,
+                state: "APPROVED".into(),
+                user: UserDto {
+                    login: "carol".into(),
+                },
+                submitted_at: Some("2026-04-08T13:00:00Z".into()),
+            },
+            ReviewDto {
+                id: 7,
+                state: "COMMENT".into(),
+                user: UserDto {
+                    login: "bob".into(),
+                },
+                submitted_at: Some("2026-04-08T12:00:00Z".into()),
+            },
+        ],
+        comments: vec![
+            ReviewCommentDto {
+                id: 2,
+                body: "reply".into(),
+                created_at: "2026-04-08T12:02:00Z".into(),
+                updated_at: Some("2026-04-08T12:03:00Z".into()),
+                user: UserDto {
+                    login: "bob".into(),
+                },
+                path: Some("src/main.rs".into()),
+                line: Some(10),
+                pull_request_review_id: Some(7),
+                original_position: Some(10),
+                position: Some(10),
+                commit_id: Some("abc123".into()),
+                original_commit_id: Some("abc123".into()),
+                diff_hunk: Some("@@ -1 +1 @@".into()),
+            },
+            ReviewCommentDto {
+                id: 1,
+                body: "root".into(),
+                created_at: "2026-04-08T12:01:00Z".into(),
+                updated_at: Some("2026-04-08T12:02:00Z".into()),
+                user: UserDto {
+                    login: "bob".into(),
+                },
+                path: Some("src/main.rs".into()),
+                line: Some(10),
+                pull_request_review_id: Some(7),
+                original_position: Some(10),
+                position: Some(10),
+                commit_id: Some("abc123".into()),
+                original_commit_id: Some("abc123".into()),
+                diff_hunk: Some("@@ -1 +1 @@".into()),
+            },
+            ReviewCommentDto {
+                id: 3,
+                body: "other thread".into(),
+                created_at: "2026-04-08T11:59:00Z".into(),
+                updated_at: None,
+                user: UserDto {
+                    login: "dave".into(),
+                },
+                path: Some("src/lib.rs".into()),
+                line: Some(22),
+                pull_request_review_id: Some(8),
+                original_position: Some(22),
+                position: Some(22),
+                commit_id: Some("def456".into()),
+                original_commit_id: Some("def456".into()),
+                diff_hunk: Some("@@ -2 +2 @@".into()),
+            },
+        ],
+        commits: vec![
+            CommitDto {
+                sha: "bbbbbbbccccccc".into(),
+                commit: RepoCommitDto {
+                    message: "fix: later commit\n\nbody".into(),
+                    author: Some(CommitUserDto {
+                        name: "Bob".into(),
+                        date: "2026-04-08T12:30:00Z".into(),
+                    }),
+                },
+            },
+            CommitDto {
+                sha: "aaaaaaabbbbbbb".into(),
+                commit: RepoCommitDto {
+                    message: "feat: earlier commit".into(),
+                    author: Some(CommitUserDto {
+                        name: "Alice".into(),
+                        date: "2026-04-08T11:30:00Z".into(),
+                    }),
+                },
+            },
+        ],
+        files: vec![
+            ChangedFileDto {
+                filename: "src/main.rs".into(),
+                additions: 5,
+                deletions: 1,
+                changes: Some(6),
+                status: Some("modified".into()),
+                previous_filename: None,
+            },
+            ChangedFileDto {
+                filename: "src/lib.rs".into(),
+                additions: 3,
+                deletions: 2,
+                changes: Some(5),
+                status: Some("modified".into()),
+                previous_filename: None,
+            },
+        ],
+    };
+
+    let doc = normalize_bundle("org/repo", bundle);
+
+    assert_eq!(doc.meta.repo, "org/repo");
+    assert_eq!(doc.meta.pr_index, 42);
+    assert_eq!(doc.meta.base_branch, "main");
+    assert_eq!(doc.meta.head_branch, "feature/x");
+
+    assert_eq!(doc.commits.len(), 2);
+    assert_eq!(doc.commits[0].title, "feat: earlier commit");
+    assert_eq!(doc.commits[0].author, "Alice");
+    assert_eq!(doc.commits[1].title, "fix: later commit");
+
+    assert_eq!(doc.reviews.len(), 2);
+    assert_eq!(doc.reviews[0].id, 7);
+    assert_eq!(doc.reviews[1].id, 8);
+
+    assert_eq!(doc.diff_stat.files_changed, 2);
+    assert_eq!(doc.diff_stat.additions, 8);
+    assert_eq!(doc.diff_stat.deletions, 3);
+    assert_eq!(doc.diff_stat.files[0].path, "src/main.rs");
+    assert_eq!(doc.diff_stat.files[1].path, "src/lib.rs");
+
+    assert_eq!(doc.threads.len(), 2);
+    assert_eq!(doc.threads[0].root_comment.id, 3);
+    assert_eq!(doc.threads[0].file_path.as_deref(), Some("src/lib.rs"));
+    assert_eq!(doc.threads[0].line, Some(22));
+    assert_eq!(doc.threads[1].root_comment.id, 1);
+    assert_eq!(doc.threads[1].replies.len(), 1);
+    assert_eq!(doc.threads[1].replies[0].id, 2);
+    assert_eq!(doc.threads[1].file_path.as_deref(), Some("src/main.rs"));
+    assert_eq!(doc.threads[1].line, Some(10));
+}