diff --git a/appwrite/client.py b/appwrite/client.py
index 35a3116..374286a 100644
--- a/appwrite/client.py
+++ b/appwrite/client.py
@@ -4,6 +4,8 @@
 import platform
 import sys
 import requests
+from concurrent.futures import ThreadPoolExecutor, as_completed
+from threading import Lock
 from .input_file import InputFile
 from .exception import AppwriteException
 from .encoders.value_class_encoder import ValueClassEncoder
@@ -186,14 +188,15 @@ def chunked_upload(
 
         if input_file.source_type == 'path':
             size = os.stat(input_file.path).st_size
-            input = open(input_file.path, 'rb')
+            input = None
         elif input_file.source_type == 'bytes':
             size = len(input_file.data)
             input = input_file.data
 
         if size < self._chunk_size:
             if input_file.source_type == 'path':
-                input_file.data = input.read()
+                with open(input_file.path, 'rb') as input:
+                    input_file.data = input.read()
 
             params[param_name] = input_file
             return self.call(
@@ -214,46 +217,103 @@ def chunked_upload(
 
         if counter > 0:
             offset = counter * self._chunk_size
-            input.seek(offset)
 
+        total_chunks = (size + self._chunk_size - 1) // self._chunk_size
+        chunks = []
         while offset < size:
-            if input_file.source_type == 'path':
-                input_file.data = input.read(self._chunk_size) or input.read(size - offset)
-            elif input_file.source_type == 'bytes':
-                if offset + self._chunk_size < size:
-                    end = offset + self._chunk_size
-                else:
-                    end = size
-                input_file.data = input[offset:end]
+            end = min(offset + self._chunk_size, size)
+            chunks.append({
+                'index': counter,
+                'start': offset,
+                'end': end,
+            })
+            offset = end
+            counter = counter + 1
 
-            params[param_name] = input_file
-            headers["content-range"] = f'bytes {offset}-{min((offset + self._chunk_size) - 1, size - 1)}/{size}'
+        if not chunks:
+            return result
+
+        def read_chunk(start, end):
+            if input_file.source_type == 'path':
+                with open(input_file.path, 'rb') as chunk_file:
+                    chunk_file.seek(start)
+                    return chunk_file.read(end - start)
+            return input[start:end]
+
+        upload_id_header = upload_id
+        completed_count = chunks[0]['index']
+        uploaded_size = chunks[0]['start']
+        progress_lock = Lock()
+        last_result = None
+        final_result = None
+
+        def is_upload_complete(chunk_result):
+            chunks_uploaded = chunk_result.get('chunksUploaded')
+            if chunks_uploaded is None:
+                return False
+            chunks_total = chunk_result.get('chunksTotal', total_chunks)
+            return int(chunks_uploaded) >= int(chunks_total)
+
+        def upload_chunk(chunk, current_upload_id):
+            chunk_input = InputFile.from_bytes(
+                read_chunk(chunk['start'], chunk['end']),
+                input_file.filename,
+                getattr(input_file, 'mime_type', None)
+            )
+            chunk_params = {**params, param_name: chunk_input}
+            chunk_headers = {**headers}
+            chunk_headers["content-range"] = f"bytes {chunk['start']}-{chunk['end'] - 1}/{size}"
+            if current_upload_id:
+                chunk_headers["x-appwrite-id"] = current_upload_id
 
-            result = self.call(
+            return self.call(
                 'post',
                 path,
-                headers,
-                params,
+                chunk_headers,
+                chunk_params,
             )
 
-            offset = offset + self._chunk_size
-
-            if "$id" in result:
-                headers["x-appwrite-id"] = result["$id"]
-
-            if on_progress is not None:
-                end = min((((counter * self._chunk_size) + self._chunk_size) - 1), size - 1)
-                on_progress({
-                    "$id": result["$id"],
-                    "progress": min(offset, size)/size * 100,
-                    "sizeUploaded": end+1,
-                    "chunksTotal": result["chunksTotal"],
-                    "chunksUploaded": result["chunksUploaded"],
-                })
-
-            counter = counter + 1
-
-        return result
+        result = upload_chunk(chunks[0], upload_id_header)
+        last_result = result
+        if "$id" in result:
+            upload_id_header = result["$id"]
+
+        completed_count = chunks[0]['index'] + 1
+        uploaded_size = chunks[0]['end']
+
+        if on_progress is not None:
+            on_progress({
+                "$id": result.get("$id"),
+                "progress": uploaded_size / size * 100,
+                "sizeUploaded": uploaded_size,
+                "chunksTotal": total_chunks,
+                "chunksUploaded": completed_count,
+            })
+
+        def upload_remaining_chunk(chunk):
+            nonlocal completed_count, uploaded_size, last_result, final_result
+            chunk_result = upload_chunk(chunk, upload_id_header)
+            with progress_lock:
+                completed_count = completed_count + 1
+                uploaded_size = uploaded_size + (chunk['end'] - chunk['start'])
+                last_result = chunk_result
+                if is_upload_complete(chunk_result):
+                    final_result = chunk_result
+                if on_progress is not None:
+                    on_progress({
+                        "$id": upload_id_header,
+                        "progress": uploaded_size / size * 100,
+                        "sizeUploaded": uploaded_size,
+                        "chunksTotal": total_chunks,
+                        "chunksUploaded": completed_count,
+                    })
+
+        with ThreadPoolExecutor(max_workers=8) as executor:
+            futures = [executor.submit(upload_remaining_chunk, chunk) for chunk in chunks[1:]]
+            for future in as_completed(futures):
+                future.result()
+
+        return final_result or last_result
 
     def flatten(self, data, prefix='', stringify=False):
         output = {}