diff --git a/src/middleware/partial-content/index.test.ts b/src/middleware/partial-content/index.test.ts
index 41e2e28c..bb73aa1f 100644
--- a/src/middleware/partial-content/index.test.ts
+++ b/src/middleware/partial-content/index.test.ts
@@ -5,7 +5,7 @@ const app = new Hono()
 
 app.use(partialContent())
 
-const body = 'Hello World with Partial Content Middleware!'
+const body = 'This is a test mock data for range requests.'
 
 app.get('/hello.jpg', (c) => {
   return c.body(body, {
@@ -17,43 +17,158 @@ app.get('/hello.jpg', (c) => {
 })
 
 describe('Partial Content Middleware', () => {
-  it('Should return 206 response with correct contents', async () => {
+  it('Should return the first 5 bytes of the mock data (bytes=0-4)', async () => {
+    const res = await app.request('/hello.jpg', {
+      headers: {
+        Range: 'bytes=0-4',
+      },
+    })
+
+    expect(res.headers.get('Content-Type')).toBe('image/jpeg')
+    expect(res.headers.get('Content-Range')).toBe('bytes 0-4/44')
+    expect(await res.text()).toBe('This ')
+  })
+
+  it('Should return the bytes from 6 to 10 (bytes=6-10)', async () => {
+    const res = await app.request('/hello.jpg', {
+      headers: {
+        Range: 'bytes=6-10',
+      },
+    })
+
+    expect(res.headers.get('Content-Type')).toBe('image/jpeg')
+    expect(res.headers.get('Content-Range')).toBe('bytes 6-10/44')
+    expect(await res.text()).toBe('s a t')
+  })
+
+  it('Should return multiple ranges of the mock data (bytes=0-4, 6-10)', async () => {
     const res = await app.request('/hello.jpg', {
       headers: {
         Range: 'bytes=0-4, 6-10',
       },
     })
-    expect(res.status).toBe(206)
-    expect(res.headers.get('Content-Type')).toMatch(
-      /^multipart\/byteranges; boundary=PARTIAL_CONTENT_BOUNDARY$/
-    )
-    expect(res.headers.get('Content-Range')).toBeNull()
-    expect(res.headers.get('Content-Length')).toBe('44')
-    expect(await res.text()).toBe(
-      [
-        '--PARTIAL_CONTENT_BOUNDARY',
-        'Content-Type: image/jpeg',
-        'Content-Range: bytes 0-4/44',
-        '',
-        'Hello',
-        '--PARTIAL_CONTENT_BOUNDARY',
-        'Content-Type: image/jpeg',
-        'Content-Range: bytes 6-10/44',
-        '',
-        'World',
-        '--PARTIAL_CONTENT_BOUNDARY--',
-        '',
-      ].join('\r\n')
+
+    expect(res.headers.get('Content-Type')).toBe(
+      'multipart/byteranges; boundary=PARTIAL_CONTENT_BOUNDARY'
     )
+
+    const expectedResponse = [
+      '--PARTIAL_CONTENT_BOUNDARY',
+      'Content-Type: image/jpeg',
+      'Content-Range: bytes 0-4/44',
+      '',
+      'This ',
+      '--PARTIAL_CONTENT_BOUNDARY',
+      'Content-Type: image/jpeg',
+      'Content-Range: bytes 6-10/44',
+      '',
+      's a t',
+      '--PARTIAL_CONTENT_BOUNDARY--',
+      '',
+    ].join('\r\n')
+    expect(await res.text()).toBe(expectedResponse)
   })
 
-  it('Should not return 206 response with invalid Range header', async () => {
+  it('Should return the last 10 bytes of the mock data (bytes=-10)', async () => {
     const res = await app.request('/hello.jpg', {
       headers: {
-        Range: 'bytes=INVALID',
+        Range: 'bytes=-10',
       },
     })
+
+    expect(res.headers.get('Content-Type')).toBe('image/jpeg')
+    expect(res.headers.get('Content-Range')).toBe('bytes 34-43/44')
+    expect(await res.text()).toBe(' requests.')
+  })
+
+  it('Should return the remaining bytes starting from byte 10 (bytes=10-)', async () => {
+    const res = await app.request('/hello.jpg', {
+      headers: {
+        Range: 'bytes=10-',
+      },
+    })
+
+    expect(res.headers.get('Content-Type')).toBe('image/jpeg')
+    expect(res.headers.get('Content-Range')).toBe('bytes 10-43/44')
+    expect(await res.text()).toBe('test mock data for range requests.')
+  })
+
+  it('Should return 416 Range Not Satisfiable for excessive number of ranges (11 or more)', async () => {
+    const res = await app.request('/hello.jpg', {
+      headers: {
+        Range: 'bytes=0-0,1-1,2-2,3-3,4-4,5-5,6-6,7-7,8-8,9-9,10-10',
+      },
+    })
+
+    expect(res.status).toBe(416)
+    expect(res.headers.get('Content-Range')).toBeNull()
+    expect(res.headers.get('Content-Length')).toBe('44')
+  })
+
+  it('Should return 404 if content is not found', async () => {
+    const app = new Hono()
+    app.use(partialContent())
+
+    app.get('/notfound.jpg', (c) => {
+      return c.notFound()
+    })
+
+    const res = await app.request('/notfound.jpg', {
+      headers: {
+        Range: 'bytes=0-10',
+      },
+    })
+
+    expect(res.status).toBe(404)
+  })
+
+  it('Should return full content if Range header is not provided', async () => {
+    const res = await app.request('/hello.jpg')
+
     expect(res.status).toBe(200)
     expect(res.headers.get('Content-Type')).toBe('image/jpeg')
+    expect(await res.text()).toBe(body) // Full body should be returned
+  })
+
+  it('Should return full content if Content-Length is missing', async () => {
+    const appWithoutContentLength = new Hono()
+    appWithoutContentLength.use(partialContent())
+
+    appWithoutContentLength.get('/hello.jpg', (c) => {
+      return c.body(body, {
+        headers: {
+          'Content-Type': 'image/jpeg',
+        },
+      })
+    })
+
+    const res = await appWithoutContentLength.request('/hello.jpg', {
+      headers: {
+        Range: 'bytes=0-4',
+      },
+    })
+
+    expect(res.status).toBe(200)
+    expect(res.headers.get('Content-Type')).toBe('image/jpeg')
+    expect(await res.text()).toBe(body)
+  })
+
+  it('Should return 204 No Content if body is missing', async () => {
+    const appWithoutBody = new Hono()
+    appWithoutBody.use(partialContent())
+
+    appWithoutBody.get('/empty.jpg', (c) => {
+      return c.body(null, 204)
+    })
+
+    const res = await appWithoutBody.request('/empty.jpg', {
+      headers: {
+        Range: 'bytes=0-4',
+      },
+    })
+
+    expect(res.status).toBe(204)
+    expect(res.headers.get('Content-Type')).toBeNull()
+    expect(await res.text()).toBe('')
   })
 })
diff --git a/src/middleware/partial-content/index.ts b/src/middleware/partial-content/index.ts
index 633b8dd2..294564ce 100644
--- a/src/middleware/partial-content/index.ts
+++ b/src/middleware/partial-content/index.ts
@@ -55,7 +55,7 @@ export const partialContent = (): MiddlewareHandler =>
     const contentLength = c.res.headers.get('Content-Length')
 
     if (rangeRequest && contentLength && c.res.body) {
-      const totalSize = parseInt(contentLength, 10)
+      const totalSize = Number(contentLength)
       const offsetSize = totalSize - 1
       const bodyStream = c.res.body.getReader()
 
@@ -74,17 +74,26 @@ export const partialContent = (): MiddlewareHandler =>
             ]
 
       if (contents.length > 10) {
-        c.header('Content-Length', undefined)
-        c.header('Content-Range', `bytes bytes */${totalSize}`)
+        c.header('Content-Length', totalSize.toString())
         c.res = c.body(null, 416)
+        return
       }
 
       const contentType = c.res.headers.get('Content-Type')
 
+      if (contents.length === 1) {
+        const part = contents[0]
+        const contentRange = formatRangeSize(part.start, part.end, totalSize)
+        c.header('Content-Range', contentRange)
+      } else {
+        c.header('Content-Type', `multipart/byteranges; boundary=${PARTIAL_CONTENT_BOUNDARY}`)
+      }
+
       const responseBody = new ReadableStream({
         async start(controller) {
           const encoder = new TextEncoder()
           const { done, value } = await bodyStream.read()
+
           if (done || !value) {
             controller.close()
             return
@@ -92,26 +101,31 @@ export const partialContent = (): MiddlewareHandler =>
 
           for (const part of contents) {
             const contentRange = formatRangeSize(part.start, part.end, totalSize)
-            controller.enqueue(
-              encoder.encode(
-                `--${PARTIAL_CONTENT_BOUNDARY}\r\nContent-Type: ${contentType}\r\nContent-Range: ${contentRange}\r\n\r\n`
-              )
-            )
-
             const sliceStart = part.start
             const sliceEnd = part.end + 1
-
             const chunk = value.subarray(sliceStart, sliceEnd)
-            controller.enqueue(chunk)
-            controller.enqueue(encoder.encode('\r\n'))
+
+            if (contents.length === 1) {
+              controller.enqueue(chunk)
+            } else {
+              controller.enqueue(
+                encoder.encode(
+                  `--${PARTIAL_CONTENT_BOUNDARY}\r\nContent-Type: ${contentType}\r\nContent-Range: ${contentRange}\r\n\r\n`
+                )
+              )
+              controller.enqueue(chunk)
+              controller.enqueue(encoder.encode('\r\n'))
+            }
+          }
+
+          if (contents.length !== 1) {
+            controller.enqueue(encoder.encode(`--${PARTIAL_CONTENT_BOUNDARY}--\r\n`))
           }
 
-          controller.enqueue(encoder.encode(`--${PARTIAL_CONTENT_BOUNDARY}--\r\n`))
           controller.close()
         },
       })
 
-      c.header('Content-Type', `multipart/byteranges; boundary=${PARTIAL_CONTENT_BOUNDARY}`)
       c.res = c.body(responseBody, 206)
     }
   }