diff --git a/Cargo.lock b/Cargo.lock
index 321a43f..aff02b8 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -314,6 +314,15 @@ version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"
 
+[[package]]
+name = "humansize"
+version = "2.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6cb51c9a029ddc91b07a787f1d86b53ccfa49b0e86688c946ebe8d3555685dd7"
+dependencies = [
+ "libm",
+]
+
 [[package]]
 name = "indexmap"
 version = "2.2.6"
@@ -357,6 +366,12 @@ version = "0.2.154"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ae743338b92ff9146ce83992f766a31066a91a8c84a45e0e9f21e7cf6de6d346"
 
+[[package]]
+name = "libm"
+version = "0.2.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4ec2a862134d2a7d32d7983ddcdd1c4923530833c9f2ea1a44fc5fa473989058"
+
 [[package]]
 name = "libredox"
 version = "0.1.3"
@@ -460,6 +475,7 @@ dependencies = [
  "clap",
  "crossterm",
  "dirs",
+ "humansize",
  "paste",
  "ratatui",
  "serde",
diff --git a/Cargo.toml b/Cargo.toml
index 5fee041..67d1e24 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,6 +15,7 @@ anyhow = "1.0.86"
 clap = { version = "4.5.4", features = ["derive"] }
 crossterm = "0.27.0"
 dirs = "5.0.1"
+humansize = "2.1.3"
 paste = "1.0.15"
 ratatui = "0.26.2"
 serde = { version = "1.0.202", features = ["derive"] }
diff --git a/src/cmd.rs b/src/cmd.rs
index 1b576ab..a25e923 100644
--- a/src/cmd.rs
+++ b/src/cmd.rs
@@ -21,6 +21,14 @@ pub struct CommandArgs {
     #[clap(short, long)]
     pub content_type: Option<ContentType>,
 
+    /// Force to no render the header.
+    #[clap(long)]
+    pub disable_header: bool,
+
+    /// Force to use the header format.
+    #[clap(short = 'f', long)]
+    pub header_format: Option<String>,
+
     /// Force to use vertical layout.
     #[clap(short = 'V', long)]
     pub vertical: bool,
diff --git a/src/config/colors.rs b/src/config/colors.rs
index 2745a4d..f9e25f8 100644
--- a/src/config/colors.rs
+++ b/src/config/colors.rs
@@ -15,6 +15,9 @@ macro_rules! generate_colors_parse {
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct Colors {
+    #[serde(default = "Colors::default_header")]
+    pub header: Color,
+
     #[serde(default = "TreeColors::default")]
     pub tree: TreeColors,
 
@@ -28,11 +31,12 @@ pub struct Colors {
     pub focus_border: Color,
 }
 
-generate_colors_parse!(Colors, tree, item, data, focus_border);
+generate_colors_parse!(Colors, header, tree, item, data, focus_border);
 
 impl Colors {
     pub fn default() -> Self {
         Self {
+            header: Self::default_header(),
             tree: TreeColors::default(),
             item: ItemColors::default(),
             data: DataColors::default(),
@@ -40,6 +44,10 @@ impl Colors {
         }
     }
 
+    fn default_header() -> Color {
+        Color::new("", "", true, false)
+    }
+
     fn default_focus_boder() -> Color {
         Color::new("magenta", "", true, false)
     }
diff --git a/src/config/mod.rs b/src/config/mod.rs
index 28d244b..4200405 100644
--- a/src/config/mod.rs
+++ b/src/config/mod.rs
@@ -17,6 +17,9 @@ pub struct Config {
     #[serde(default = "Layout::default")]
     pub layout: Layout,
 
+    #[serde(default = "Header::default")]
+    pub header: Header,
+
     #[serde(default = "Colors::default")]
     pub colors: Colors,
 
@@ -44,6 +47,15 @@ pub enum LayoutDirection {
     Horizontal,
 }
 
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct Header {
+    #[serde(default = "Header::default_disable")]
+    pub disable: bool,
+
+    #[serde(default = "Header::default_format")]
+    pub format: String,
+}
+
 impl Config {
     pub const MIN_LAYOUT_TREE_SIZE: u16 = 10;
     pub const MAX_LAYOUT_TREE_SIZE: u16 = 80;
@@ -105,6 +117,7 @@ impl Config {
     pub fn default() -> Self {
         Self {
             layout: Layout::default(),
+            header: Header::default(),
             colors: Colors::default(),
             types: Types::default(),
             keys: Keys::default(),
@@ -134,3 +147,20 @@ impl Layout {
         40
     }
 }
+
+impl Header {
+    fn default() -> Self {
+        Self {
+            disable: Self::default_disable(),
+            format: Self::default_format(),
+        }
+    }
+
+    fn default_disable() -> bool {
+        false
+    }
+
+    fn default_format() -> String {
+        "{version} - {data_source} ({content_type}) - {data_size}".to_string()
+    }
+}
diff --git a/src/main.rs b/src/main.rs
index a2438df..aa549b1 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -18,7 +18,7 @@ use crate::cmd::CommandArgs;
 use crate::config::Config;
 use crate::config::LayoutDirection;
 use crate::tree::{ContentType, Tree};
-use crate::ui::app::App;
+use crate::ui::{App, HeaderContext};
 
 // Forbid large data size to ensure TUI performance
 const MAX_DATA_SIZE: usize = 10 * 1024 * 1024;
@@ -50,8 +50,7 @@ fn run() -> Result<()> {
     let mut cfg = if args.ignore_config {
         Config::default()
     } else {
-        let config_path = args.config.clone();
-        Config::load(config_path)?
+        Config::load(args.config)?
     };
 
     if args.vertical && args.horizontal {
@@ -64,6 +63,14 @@ fn run() -> Result<()> {
         cfg.layout.direction = LayoutDirection::Horizontal;
     }
 
+    if args.disable_header {
+        cfg.header.disable = true;
+    }
+
+    if let Some(format) = args.header_format {
+        cfg.header.format = format;
+    }
+
     if let Some(size) = args.size {
         cfg.layout.tree_size = size;
     }
@@ -126,6 +133,12 @@ fn run() -> Result<()> {
     let tree = Tree::parse(&cfg, &data, content_type).context("parse file")?;
 
     let mut app = App::new(&cfg, tree);
+
+    if !cfg.header.disable {
+        let header_ctx = HeaderContext::new(args.path, content_type, data.len());
+        app.set_header(header_ctx);
+    }
+
     app.show().context("show tui")?;
 
     Ok(())
diff --git a/src/ui/app.rs b/src/ui/app.rs
index b778096..0917788 100644
--- a/src/ui/app.rs
+++ b/src/ui/app.rs
@@ -11,6 +11,7 @@ use crate::config::keys::Action;
 use crate::config::{Config, LayoutDirection};
 use crate::tree::Tree;
 use crate::ui::data_block::DataBlock;
+use crate::ui::header::{Header, HeaderContext};
 use crate::ui::tree_overview::TreeOverview;
 
 enum Refresh {
@@ -48,9 +49,15 @@ pub struct App<'a> {
 
     layout_direction: LayoutDirection,
     layout_tree_size: u16,
+
+    header: Option<Header<'a>>,
+    header_area: Rect,
+    skip_header: bool,
 }
 
 impl<'a> App<'a> {
+    const HEADER_HEIGHT: u16 = 1;
+
     pub fn new(cfg: &'a Config, tree: Tree<'a>) -> Self {
         Self {
             cfg,
@@ -62,6 +69,9 @@ impl<'a> App<'a> {
             data_block_area: Rect::default(),
             layout_direction: cfg.layout.direction,
             layout_tree_size: cfg.layout.tree_size,
+            header: None,
+            header_area: Rect::default(),
+            skip_header: false,
         }
     }
 
@@ -114,6 +124,10 @@ impl<'a> App<'a> {
         }
     }
 
+    pub fn set_header(&mut self, ctx: HeaderContext) {
+        self.header = Some(Header::new(self.cfg, ctx));
+    }
+
     fn draw(&mut self, frame: &mut Frame) {
         self.refresh_area(frame);
 
@@ -125,6 +139,12 @@ impl<'a> App<'a> {
             // TODO: When we cannot find data, should warn user (maybe message in data block?)
         }
 
+        if let Some(header) = self.header.as_ref() {
+            if !self.skip_header {
+                header.draw(frame, self.header_area);
+            }
+        }
+
         let tree_focus = matches!(self.focus, ElementInFocus::TreeOverview);
         self.tree_overview
             .draw(frame, self.tree_overview_area, tree_focus);
@@ -136,7 +156,37 @@ impl<'a> App<'a> {
 
     fn refresh_area(&mut self, frame: &Frame) {
         let tree_size = self.layout_tree_size;
-        let data_size = 100 - tree_size;
+        let data_size = 100_u16.saturating_sub(tree_size);
+
+        // These checks should be done in config validation.
+        debug_assert_ne!(tree_size, 0);
+        debug_assert_ne!(data_size, 0);
+
+        let frame_area = frame.size();
+        let main_area = match self.header {
+            Some(_) => {
+                let Rect { height, .. } = frame_area;
+                if height <= Self::HEADER_HEIGHT + 1 {
+                    // God knows under what circumstances such a small terminal would appear!
+                    // We will not render the header.
+                    self.skip_header = true;
+                    frame_area
+                } else {
+                    self.skip_header = false;
+                    self.header_area = Rect {
+                        height: Self::HEADER_HEIGHT,
+                        y: 0,
+                        ..frame_area
+                    };
+                    Rect {
+                        height: height.saturating_sub(Self::HEADER_HEIGHT),
+                        y: Self::HEADER_HEIGHT,
+                        ..frame_area
+                    }
+                }
+            }
+            None => frame_area,
+        };
 
         match self.layout_direction {
             LayoutDirection::Vertical => {
@@ -144,14 +194,14 @@ impl<'a> App<'a> {
                     Constraint::Percentage(tree_size),
                     Constraint::Percentage(data_size),
                 ]);
-                [self.tree_overview_area, self.data_block_area] = vertical.areas(frame.size());
+                [self.tree_overview_area, self.data_block_area] = vertical.areas(main_area);
             }
             LayoutDirection::Horizontal => {
                 let horizontal = Layout::horizontal([
                     Constraint::Percentage(tree_size),
                     Constraint::Percentage(data_size),
                 ]);
-                [self.tree_overview_area, self.data_block_area] = horizontal.areas(frame.size());
+                [self.tree_overview_area, self.data_block_area] = horizontal.areas(main_area);
             }
         }
     }
diff --git a/src/ui/data_block.rs b/src/ui/data_block.rs
index bd686db..83b2d97 100644
--- a/src/ui/data_block.rs
+++ b/src/ui/data_block.rs
@@ -9,7 +9,7 @@ use crate::config::keys::Action;
 use crate::config::Config;
 use crate::ui::app::ScrollDirection;
 
-pub struct DataBlock<'a> {
+pub(super) struct DataBlock<'a> {
     cfg: &'a Config,
     data: String,
 
@@ -29,7 +29,7 @@ pub struct DataBlock<'a> {
 impl<'a> DataBlock<'a> {
     const SCROLL_RETAIN: usize = 5;
 
-    pub fn new(cfg: &'a Config) -> Self {
+    pub(super) fn new(cfg: &'a Config) -> Self {
         Self {
             cfg,
             data: String::new(),
@@ -45,7 +45,7 @@ impl<'a> DataBlock<'a> {
         }
     }
 
-    pub fn on_key(&mut self, action: Action) -> bool {
+    pub(super) fn on_key(&mut self, action: Action) -> bool {
         match action {
             Action::MoveDown => self.scroll_down(1),
             Action::MoveUp => self.scroll_up(1),
@@ -57,14 +57,14 @@ impl<'a> DataBlock<'a> {
         }
     }
 
-    pub fn on_scroll(&mut self, direction: ScrollDirection) -> bool {
+    pub(super) fn on_scroll(&mut self, direction: ScrollDirection) -> bool {
         match direction {
             ScrollDirection::Up => self.scroll_up(3),
             ScrollDirection::Down => self.scroll_down(3),
         }
     }
 
-    pub fn scroll_first(&mut self) -> bool {
+    pub(super) fn scroll_first(&mut self) -> bool {
         let can_scroll = self.can_vertical_scroll || self.can_horizontal_scroll;
         let scroll_first = self.vertical_scroll == 0 && self.horizontal_scroll == 0;
 
@@ -81,7 +81,7 @@ impl<'a> DataBlock<'a> {
         true
     }
 
-    pub fn scroll_last(&mut self) -> bool {
+    pub(super) fn scroll_last(&mut self) -> bool {
         if !self.can_vertical_scroll || self.vertical_scroll == self.vertical_scroll_last {
             return false;
         }
@@ -94,7 +94,7 @@ impl<'a> DataBlock<'a> {
         true
     }
 
-    pub fn scroll_down(&mut self, lines: usize) -> bool {
+    pub(super) fn scroll_down(&mut self, lines: usize) -> bool {
         if !self.can_vertical_scroll || self.vertical_scroll == self.vertical_scroll_last {
             return false;
         }
@@ -107,7 +107,7 @@ impl<'a> DataBlock<'a> {
         true
     }
 
-    pub fn scroll_up(&mut self, lines: usize) -> bool {
+    pub(super) fn scroll_up(&mut self, lines: usize) -> bool {
         if !self.can_vertical_scroll || self.vertical_scroll == 0 {
             return false;
         }
@@ -117,7 +117,7 @@ impl<'a> DataBlock<'a> {
         true
     }
 
-    pub fn scroll_right(&mut self, lines: usize) -> bool {
+    pub(super) fn scroll_right(&mut self, lines: usize) -> bool {
         if !self.can_horizontal_scroll || self.horizontal_scroll == self.horizontal_scroll_last {
             return false;
         }
@@ -131,7 +131,7 @@ impl<'a> DataBlock<'a> {
         true
     }
 
-    pub fn scroll_left(&mut self, lines: usize) -> bool {
+    pub(super) fn scroll_left(&mut self, lines: usize) -> bool {
         if self.horizontal_scroll == 0 {
             return false;
         }
@@ -142,7 +142,7 @@ impl<'a> DataBlock<'a> {
         true
     }
 
-    pub fn update_data(&mut self, data: String, area: Rect) {
+    pub(super) fn update_data(&mut self, data: String, area: Rect) {
         if self.data == data.as_str() && self.last_area == area {
             // No need to update data and scroll state.
             return;
@@ -187,7 +187,7 @@ impl<'a> DataBlock<'a> {
         self.last_area = area;
     }
 
-    pub fn draw(&mut self, frame: &mut Frame, area: Rect, focus: bool) {
+    pub(super) fn draw(&mut self, frame: &mut Frame, area: Rect, focus: bool) {
         let (border_style, border_type) = super::get_border_style(
             &self.cfg.colors.focus_border,
             &self.cfg.colors.data.border,
diff --git a/src/ui/header.rs b/src/ui/header.rs
new file mode 100644
index 0000000..36dbfeb
--- /dev/null
+++ b/src/ui/header.rs
@@ -0,0 +1,65 @@
+use std::borrow::Cow;
+
+use ratatui::layout::{Alignment, Rect};
+use ratatui::text::Span;
+use ratatui::widgets::Paragraph;
+use ratatui::Frame;
+
+use crate::config::Config;
+use crate::tree::ContentType;
+
+pub struct HeaderContext {
+    version: String,
+    data_source: Cow<'static, str>,
+    content_type: &'static str,
+    data_size: String,
+}
+
+impl HeaderContext {
+    pub fn new(source: Option<String>, content_type: ContentType, size: usize) -> Self {
+        let version = format!("otree {}", env!("CARGO_PKG_VERSION"));
+        let source = source.map(Cow::Owned).unwrap_or(Cow::Borrowed("stdin"));
+        let content_type = match content_type {
+            ContentType::Toml => "toml",
+            ContentType::Yaml => "yaml",
+            ContentType::Json => "json",
+        };
+
+        let data_size = humansize::format_size(size, humansize::BINARY);
+
+        Self {
+            version,
+            data_source: source,
+            content_type,
+            data_size,
+        }
+    }
+
+    fn format(&self, s: &str) -> String {
+        let s = s.replace("{version}", &self.version);
+        let s = s.replace("{data_source}", &self.data_source);
+        let s = s.replace("{content_type}", self.content_type);
+        s.replace("{data_size}", &self.data_size)
+    }
+}
+
+pub(super) struct Header<'a> {
+    cfg: &'a Config,
+    data: String,
+}
+
+impl<'a> Header<'a> {
+    pub(super) fn new(cfg: &'a Config, ctx: HeaderContext) -> Self {
+        Self {
+            cfg,
+            data: ctx.format(&cfg.header.format),
+        }
+    }
+
+    pub(super) fn draw(&self, frame: &mut Frame, area: Rect) {
+        let span = Span::styled(self.data.as_str(), self.cfg.colors.header.style);
+        // TODO: Allow user to customize alignment.
+        let paragraph = Paragraph::new(span).alignment(Alignment::Center);
+        frame.render_widget(paragraph, area);
+    }
+}
diff --git a/src/ui/mod.rs b/src/ui/mod.rs
index 19626f9..3b181ff 100644
--- a/src/ui/mod.rs
+++ b/src/ui/mod.rs
@@ -3,9 +3,13 @@ use ratatui::widgets::BorderType;
 
 use crate::config::colors::Color;
 
-pub mod app;
-pub mod data_block;
-pub mod tree_overview;
+mod app;
+mod data_block;
+mod header;
+mod tree_overview;
+
+pub use app::App;
+pub use header::HeaderContext;
 
 fn get_border_style(focus_color: &Color, normal_color: &Color, focus: bool) -> (Style, BorderType) {
     let color = if focus { focus_color } else { normal_color };
diff --git a/src/ui/tree_overview.rs b/src/ui/tree_overview.rs
index d607594..9d0c03f 100644
--- a/src/ui/tree_overview.rs
+++ b/src/ui/tree_overview.rs
@@ -10,7 +10,7 @@ use crate::config::Config;
 use crate::tree::Tree;
 use crate::ui::app::ScrollDirection;
 
-pub struct TreeOverview<'a> {
+pub(super) struct TreeOverview<'a> {
     cfg: &'a Config,
     state: TreeState<String>,
     tree: Option<Tree<'a>>,
@@ -19,7 +19,7 @@ pub struct TreeOverview<'a> {
 }
 
 impl<'a> TreeOverview<'a> {
-    pub fn new(cfg: &'a Config, tree: Tree<'a>) -> Self {
+    pub(super) fn new(cfg: &'a Config, tree: Tree<'a>) -> Self {
         Self {
             cfg,
             state: TreeState::default(),
@@ -29,7 +29,7 @@ impl<'a> TreeOverview<'a> {
         }
     }
 
-    pub fn get_selected(&self) -> Option<String> {
+    pub(super) fn get_selected(&self) -> Option<String> {
         let selected = self.state.get_selected();
         if selected.is_empty() {
             return None;
@@ -38,11 +38,11 @@ impl<'a> TreeOverview<'a> {
         Some(selected.join("/"))
     }
 
-    pub fn get_data(&self, id: &str) -> Option<String> {
+    pub(super) fn get_data(&self, id: &str) -> Option<String> {
         self.tree().details.get(id).map(|d| d.value.clone())
     }
 
-    pub fn on_key(&mut self, action: Action) -> bool {
+    pub(super) fn on_key(&mut self, action: Action) -> bool {
         match action {
             Action::MoveUp => self.state.key_up(),
             Action::MoveDown => self.state.key_down(),
@@ -140,7 +140,7 @@ impl<'a> TreeOverview<'a> {
         Some(parent)
     }
 
-    pub fn on_click(&mut self, index: u16) {
+    pub(super) fn on_click(&mut self, index: u16) {
         let offset = self.state.get_offset();
         let index = (index as usize) + offset;
 
@@ -150,14 +150,14 @@ impl<'a> TreeOverview<'a> {
         }
     }
 
-    pub fn on_scroll(&mut self, direction: ScrollDirection) -> bool {
+    pub(super) fn on_scroll(&mut self, direction: ScrollDirection) -> bool {
         match direction {
             ScrollDirection::Up => self.state.scroll_up(1),
             ScrollDirection::Down => self.state.scroll_down(1),
         }
     }
 
-    pub fn draw(&mut self, frame: &mut Frame, area: Rect, focus: bool) {
+    pub(super) fn draw(&mut self, frame: &mut Frame, area: Rect, focus: bool) {
         let (border_style, border_type) = super::get_border_style(
             &self.cfg.colors.focus_border,
             &self.cfg.colors.tree.border,