diff --git a/src/args.rs b/src/args.rs
index e2cf186..58163e1 100644
--- a/src/args.rs
+++ b/src/args.rs
@@ -643,6 +643,10 @@ pub struct Arg {
     #[arg(long, global = true)]
     /// Path to qlie pack archive key file (pack_keyfile_kfueheish15538fa9or.key)
     pub qlie_pack_keyfile: Option<String>,
+    #[cfg(feature = "qlie-arc")]
+    #[arg(long, global = true, action = ArgAction::SetTrue)]
+    /// Whether to compress files in Qlie pack archive.
+    pub qlie_pack_compress_files: bool,
     #[command(subcommand)]
     /// Command
     pub command: Command,
diff --git a/src/main.rs b/src/main.rs
index e3c5d23..dff2c3b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -3357,6 +3357,8 @@ fn main() {
         qlie_abmp10_process_abmp10: !arg.qlie_abmp10_no_process_abmp10,
         #[cfg(feature = "qlie-arc")]
         qlie_pack_keyfile: arg.qlie_pack_keyfile.clone(),
+        #[cfg(feature = "qlie-arc")]
+        qlie_pack_compress_files: arg.qlie_pack_compress_files,
     });
     match &arg.command {
         args::Command::Export { input, output } => {
diff --git a/src/scripts/qlie/archive/pack/encryption.rs b/src/scripts/qlie/archive/pack/encryption.rs
index 3b52b68..4741bae 100644
--- a/src/scripts/qlie/archive/pack/encryption.rs
+++ b/src/scripts/qlie/archive/pack/encryption.rs
@@ -5,7 +5,7 @@ use crate::types::*;
 use crate::utils::encoding::*;
 use crate::utils::mmx::*;
 use anyhow::Result;
-use std::io::{Read, Write};
+use std::io::{Read, Seek, SeekFrom, Write};
 
 pub trait Hasher {
     fn update(&mut self, data: &[u8]) -> Result<()>;
@@ -667,3 +667,257 @@ impl<'a> Read for Decompressor<'a> {
         Ok(used)
     }
 }
+
+pub struct Compressor<W: Write + Seek> {
+    stream: W,
+    buffer: Vec<u8>,
+    total_unpacked_size: u32,
+    is_finished: bool,
+}
+
+impl<W: Write + Seek> Compressor<W> {
+    pub fn new(mut stream: W) -> Result<Self> {
+        stream.write_u32(0xFF435031)?;
+        stream.write_u32(0)?;
+        stream.write_u32(0)?;
+        Ok(Self {
+            stream,
+            buffer: Vec::new(),
+            total_unpacked_size: 0,
+            is_finished: false,
+        })
+    }
+
+    pub fn finish(&mut self) -> Result<()> {
+        if self.is_finished {
+            return Ok(());
+        }
+        if !self.buffer.is_empty() {
+            self.flush_block()?;
+        }
+        let pos = self.stream.stream_position()?;
+        self.stream.seek(SeekFrom::Start(8))?;
+        self.stream.write_u32(self.total_unpacked_size)?;
+        self.stream.seek(SeekFrom::Start(pos))?;
+        self.is_finished = true;
+        Ok(())
+    }
+
+    fn flush_block(&mut self) -> Result<()> {
+        if self.buffer.is_empty() {
+            return Ok(());
+        }
+        let (table, data) = compress_algo(&self.buffer);
+
+        // Write table
+        write_table(&mut self.stream, &table)?;
+
+        // Write block size
+        self.stream.write_u32(data.len() as u32)?;
+        self.stream.write_all(&data)?;
+
+        self.total_unpacked_size += self.buffer.len() as u32;
+        self.buffer.clear();
+        Ok(())
+    }
+}
+
+impl<W: Write + Seek> Write for Compressor<W> {
+    fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
+        let mut pos = 0;
+        while pos < buf.len() {
+            let space = 0x10000 - self.buffer.len();
+            let copy = space.min(buf.len() - pos);
+            self.buffer.extend_from_slice(&buf[pos..pos + copy]);
+            pos += copy;
+            if self.buffer.len() >= 0x10000 {
+                self.flush_block()
+                    .map_err(|e| std::io::Error::new(std::io::ErrorKind::Other, e))?;
+            }
+        }
+        Ok(buf.len())
+    }
+
+    fn flush(&mut self) -> std::io::Result<()> {
+        self.stream.flush()
+    }
+}
+
+impl<W: Write + Seek> Drop for Compressor<W> {
+    fn drop(&mut self) {
+        let _ = self.finish();
+    }
+}
+
+fn write_table<W: Write>(writer: &mut W, table: &[[u8; 2]; 256]) -> Result<()> {
+    let mut i = 0;
+    while i < 256 {
+        // Count consecutive identities
+        let mut n_identities = 0;
+        let mut j = i;
+        while j < 256 && table[j][0] == j as u8 {
+            n_identities += 1;
+            j += 1;
+        }
+
+        if n_identities > 0 {
+            let k = n_identities.min(128);
+            if i + k == 256 {
+                writer.write_u8(127 + k as u8)?;
+                i += k;
+            } else {
+                writer.write_u8(127 + k as u8)?;
+                i += k;
+                // Write explicit
+                writer.write_u8(table[i][0])?;
+                if table[i][0] != i as u8 {
+                    writer.write_u8(table[i][1])?;
+                }
+                i += 1;
+            }
+        } else {
+            let mut count = 0;
+            let mut j = i;
+            while j < 256 && count < 128 {
+                if j + 1 < 256 && table[j][0] == j as u8 && table[j + 1][0] == (j + 1) as u8 {
+                    break;
+                }
+                count += 1;
+                j += 1;
+            }
+
+            writer.write_u8((count - 1) as u8)?;
+            for k in 0..count {
+                let curr = i + k;
+                writer.write_u8(table[curr][0])?;
+                if table[curr][0] != curr as u8 {
+                    writer.write_u8(table[curr][1])?;
+                }
+            }
+            i += count;
+        }
+    }
+    Ok(())
+}
+
+fn compress_algo(input: &[u8]) -> ([[u8; 2]; 256], Vec<u8>) {
+    let mut tokens = input.to_vec();
+    let mut table = [[0u8; 2]; 256];
+    for i in 0..256 {
+        table[i][0] = i as u8;
+    }
+
+    let max_iterations = 256;
+    for _ in 0..max_iterations {
+        let mut pair_counts = vec![0u32; 65536];
+        let mut max_pair_idx = 0;
+        let mut max_pair_count = 0;
+
+        if tokens.len() < 2 {
+            break;
+        }
+
+        for i in 0..tokens.len() - 1 {
+            let pair = ((tokens[i] as usize) << 8) | (tokens[i + 1] as usize);
+            pair_counts[pair] += 1;
+            if pair_counts[pair] > max_pair_count {
+                max_pair_count = pair_counts[pair];
+                max_pair_idx = pair;
+            }
+        }
+
+        // Must appear at least twice to save space (2 bytes * 2 -> 1 byte * 2 + overhead)
+        if max_pair_count < 2 {
+            break;
+        }
+
+        let is_used = get_used_tokens(&tokens, &table);
+        let mut unused = None;
+        for i in 0..256 {
+            if !is_used[i] {
+                unused = Some(i as u8);
+                break;
+            }
+        }
+
+        if let Some(token) = unused {
+            let left = (max_pair_idx >> 8) as u8;
+            let right = (max_pair_idx & 0xFF) as u8;
+
+            table[token as usize] = [left, right];
+
+            let mut new_tokens = Vec::with_capacity(tokens.len());
+            let mut i = 0;
+            while i < tokens.len() {
+                if i + 1 < tokens.len() && tokens[i] == left && tokens[i + 1] == right {
+                    new_tokens.push(token);
+                    i += 2;
+                } else {
+                    new_tokens.push(tokens[i]);
+                    i += 1;
+                }
+            }
+            tokens = new_tokens;
+        } else {
+            break;
+        }
+    }
+    (table, tokens)
+}
+
+fn get_used_tokens(tokens: &[u8], table: &[[u8; 2]; 256]) -> [bool; 256] {
+    let mut used = [false; 256];
+    let mut stack = Vec::with_capacity(256);
+
+    // Mark direct tokens
+    for &t in tokens {
+        if !used[t as usize] {
+            used[t as usize] = true;
+            stack.push(t);
+        }
+    }
+
+    // Propagate
+    while let Some(t) = stack.pop() {
+        // If t is composite, mark children
+        // Check if t is composite: table[t][0] != t
+        let t_idx = t as usize;
+        if table[t_idx][0] != t {
+            let l = table[t_idx][0];
+            let r = table[t_idx][1];
+
+            if !used[l as usize] {
+                used[l as usize] = true;
+                stack.push(l);
+            }
+            if !used[r as usize] {
+                used[r as usize] = true;
+                stack.push(r);
+            }
+        }
+    }
+    used
+}
+
+pub fn compress(data: &[u8]) -> Result<Vec<u8>> {
+    let mut cursor = std::io::Cursor::new(Vec::new());
+    {
+        let mut compressor = Compressor::new(&mut cursor)?;
+        compressor.write_all(data)?;
+        compressor.finish()?;
+    }
+    Ok(cursor.into_inner())
+}
+
+#[test]
+fn test_compress_decompress() -> Result<()> {
+    let data = b"The quick brown fox jumps over the lazy dog.".repeat(100);
+    println!("Original size: {}", data.len());
+    let compressed = compress(&data)?;
+    println!("Compressed size: {}", compressed.len());
+    let mut decompressed = decompress(Box::new(MemReaderRef::new(&compressed)))?;
+    let mut output = Vec::new();
+    decompressed.read_to_end(&mut output)?;
+    assert_eq!(data.as_slice(), output.as_slice());
+    Ok(())
+}
diff --git a/src/scripts/qlie/archive/pack/v31.rs b/src/scripts/qlie/archive/pack/v31.rs
index e68c6b3..7a9989e 100644
--- a/src/scripts/qlie/archive/pack/v31.rs
+++ b/src/scripts/qlie/archive/pack/v31.rs
@@ -122,6 +122,7 @@ pub struct QliePackArchiveWriterV31<T: Write + Seek> {
     entries: Vec<QlieEntry>,
     key: u32,
     common_key: Option<Vec<u8>>,
+    compress_files: bool,
 }
 
 struct FilenameEntry {
@@ -239,6 +240,7 @@ impl<T: Write + Seek> QliePackArchiveWriterV31<T> {
             entries,
             key,
             common_key: None,
+            compress_files: config.qlie_pack_compress_files,
         };
         if !has_key_file {
             let key_path = config.qlie_pack_keyfile.as_ref().unwrap();
@@ -317,6 +319,7 @@ struct Writer2<'a, T: Write + Seek> {
     entry_idx: usize,
     mem: MemWriter,
     is_v1: bool,
+    compress_file: bool,
 }
 
 impl<'a, T: Write + Seek> Writer2<'a, T> {
@@ -341,6 +344,29 @@ impl<'a, T: Write + Seek> Writer2<'a, T> {
             self.inner.common_key = Some(get_common_key(&self.mem.data)?);
         } else {
             compute.entry.is_encrypted = 2;
+            let data = if self.compress_file {
+                let compressed = compress(&self.mem.data)?;
+                if compressed.len() >= self.mem.data.len() {
+                    let mut nw = MemWriter::new();
+                    std::mem::swap(&mut self.mem, &mut nw);
+                    nw.into_inner()
+                } else {
+                    compute.entry.is_packed = 1;
+                    compute.entry.size = compressed.len() as u32;
+                    // {
+                    //     let mut decom = decompress(Box::new(MemReaderRef::new(&compressed)))?;
+                    //     let mut decompressed = Vec::new();
+                    //     decom.read_to_end(&mut decompressed)?;
+                    //     println!("File: {}, Original Size: {}, Compressed Size: {}", compute.entry.name, decompressed.len(), compressed.len());
+                    //     assert_eq!(self.mem.data.as_slice(), decompressed.as_slice());
+                    // }
+                    compressed
+                }
+            } else {
+                let mut nw = MemWriter::new();
+                std::mem::swap(&mut self.mem, &mut nw);
+                nw.into_inner()
+            };
             let name = compute.entry.name.clone();
             let common_key = self
                 .inner
@@ -349,12 +375,12 @@ impl<'a, T: Write + Seek> Writer2<'a, T> {
                 .ok_or_else(|| anyhow::anyhow!("Common key is not available"))?;
             let mut encryptor = Encryption31EncryptV2::new(
                 compute,
-                size,
+                data.len() as u32,
                 name,
                 self.inner.key,
                 common_key.to_vec(),
             )?;
-            encryptor.write_all(&self.mem.data)?;
+            encryptor.write_all(&data)?;
         }
         Ok(())
     }
@@ -465,19 +491,23 @@ impl<T: Write + Seek> Archive for QliePackArchiveWriterV31<T> {
                 entry_idx,
                 mem: MemWriter::new(),
                 is_v1: true,
+                // Disable compression for key file
+                compress_file: false,
             }));
         }
-        if size.is_none() {
+        if size.is_none() || self.compress_files {
             let entry_idx = self
                 .entries
                 .iter()
                 .position(|e| e.name == name)
                 .ok_or_else(|| anyhow::anyhow!("File {} not found in entries", name))?;
+            let compress_file = self.compress_files;
             return Ok(Box::new(Writer2 {
                 inner: self,
                 entry_idx,
                 mem: MemWriter::new(),
                 is_v1: false,
+                compress_file,
             }));
         }
         let entry_idx = self
diff --git a/src/types.rs b/src/types.rs
index 9f798cd..731cb78 100644
--- a/src/types.rs
+++ b/src/types.rs
@@ -599,6 +599,9 @@ pub struct ExtraConfig {
     #[cfg(feature = "qlie-arc")]
     /// Path to qlie pack archive key file (pack_keyfile_kfueheish15538fa9or.key)
     pub qlie_pack_keyfile: Option<String>,
+    #[cfg(feature = "qlie-arc")]
+    /// Whether to compress files in Qlie pack archive.
+    pub qlie_pack_compress_files: bool,
 }
 
 #[derive(Clone, Copy, Debug, ValueEnum, PartialEq, Eq, PartialOrd, Ord)]