diff --git a/api/public/swagger.yaml b/api/public/swagger.yaml
index b4f9ebd..ccb2f70 100644
--- a/api/public/swagger.yaml
+++ b/api/public/swagger.yaml
@@ -539,7 +539,9 @@ paths:
                     content:
                         application/json:
                             schema:
-                                $ref: '#/components/schemas/ExecuteReturnJsonResponse'
+                                anyOf:
+                                    - {$ref: '#/components/schemas/ExecuteReturnJsonResponse'}
+                                    - {type: string, format: byte}
             description: 'Execute SAS code.'
             summary: 'Run SAS Code and returns log'
             tags:
@@ -1054,7 +1056,9 @@ paths:
                     content:
                         application/json:
                             schema:
-                                type: string
+                                anyOf:
+                                    - {type: string}
+                                    - {type: string, format: byte}
             description: "Trigger a SAS program using it's location in the _program parameter.\nEnable debugging using the _debug parameter.\nAdditional URL parameters are turned into SAS macro variables.\nAny files provided are placed into the session and\ncorresponding _WEBIN_XXX variables are created."
             summary: 'Execute Stored Program, return raw content'
             tags:
@@ -1078,7 +1082,9 @@ paths:
                     content:
                         application/json:
                             schema:
-                                $ref: '#/components/schemas/ExecuteReturnJsonResponse'
+                                anyOf:
+                                    - {$ref: '#/components/schemas/ExecuteReturnJsonResponse'}
+                                    - {type: string, format: byte}
                             examples:
                                 'Example 1':
                                     value: {status: success, _webout: 'webout content', log: [], httpHeaders: {Content-type: application/zip, Cache-Control: 'public, max-age=1000'}}
diff --git a/api/src/controllers/code.ts b/api/src/controllers/code.ts
index c5c8e65..85e3d54 100644
--- a/api/src/controllers/code.ts
+++ b/api/src/controllers/code.ts
@@ -25,7 +25,7 @@ export class CodeController {
   public async executeSASCode(
     @Request() request: express.Request,
     @Body() body: ExecuteSASCodePayload
-  ): Promise<ExecuteReturnJsonResponse> {
+  ): Promise<ExecuteReturnJsonResponse | Buffer> {
     return executeSASCode(request, body)
   }
 }
@@ -41,6 +41,11 @@ const executeSASCode = async (req: any, { code }: ExecuteSASCodePayload) => {
         true
       )) as ExecuteReturnJson
 
+    if (webout instanceof Buffer) {
+      ;(req as any).sasHeaders = httpHeaders
+      return webout
+    }
+
     return {
       status: 'success',
       _webout: webout,
diff --git a/api/src/controllers/internal/Execution.ts b/api/src/controllers/internal/Execution.ts
index f452912..6856923 100644
--- a/api/src/controllers/internal/Execution.ts
+++ b/api/src/controllers/internal/Execution.ts
@@ -1,7 +1,13 @@
 import path from 'path'
 import fs from 'fs'
 import { getSessionController } from './'
-import { readFile, fileExists, createFile, moveFile } from '@sasjs/utils'
+import {
+  readFile,
+  fileExists,
+  createFile,
+  moveFile,
+  readFileBinary
+} from '@sasjs/utils'
 import { PreProgramVars, TreeNode } from '../../types'
 import {
   extractHeaders,
@@ -16,12 +22,12 @@ export interface ExecutionVars {
 
 export interface ExecuteReturnRaw {
   httpHeaders: HTTPHeaders
-  result: string
+  result: string | Buffer
 }
 
 export interface ExecuteReturnJson {
   httpHeaders: HTTPHeaders
-  webout: string
+  webout: string | Buffer
   log?: string
 }
 
@@ -138,15 +144,17 @@ ${program}`
     }
 
     const log = (await fileExists(logPath)) ? await readFile(logPath) : ''
-    const webout = (await fileExists(weboutPath))
-      ? await readFile(weboutPath)
-      : ''
     const headersContent = (await fileExists(headersPath))
       ? await readFile(headersPath)
       : ''
-    const httpHeaders: HTTPHeaders = headersContent
-      ? extractHeaders(headersContent)
-      : {}
+    const httpHeaders: HTTPHeaders = extractHeaders(headersContent)
+    const fileResponse: boolean = httpHeaders.hasOwnProperty('content-type')
+
+    const webout = (await fileExists(weboutPath))
+      ? fileResponse
+        ? await readFileBinary(weboutPath)
+        : await readFile(weboutPath)
+      : ''
 
     const debugValue =
       typeof vars._debug === 'string' ? parseInt(vars._debug) : vars._debug
@@ -165,10 +173,11 @@ ${program}`
 
     return {
       httpHeaders,
-      result:
-        (debugValue && debugValue >= 131) || session.crashed
-          ? `<html><body>${webout}<div style="text-align:left"><hr /><h2>SAS Log</h2><pre>${log}</pre></div></body></html>`
-          : webout
+      result: fileResponse
+        ? webout
+        : (debugValue && debugValue >= 131) || session.crashed
+        ? `<html><body>${webout}<div style="text-align:left"><hr /><h2>SAS Log</h2><pre>${log}</pre></div></body></html>`
+        : webout
     }
   }
 
diff --git a/api/src/controllers/stp.ts b/api/src/controllers/stp.ts
index f5fff74..2335e5e 100644
--- a/api/src/controllers/stp.ts
+++ b/api/src/controllers/stp.ts
@@ -59,7 +59,7 @@ export class STPController {
   public async executeReturnRaw(
     @Request() request: express.Request,
     @Query() _program: string
-  ): Promise<string> {
+  ): Promise<string | Buffer> {
     return executeReturnRaw(request, _program)
   }
 
@@ -87,7 +87,7 @@ export class STPController {
     @Request() request: express.Request,
     @Body() body?: ExecuteReturnJsonPayload,
     @Query() _program?: string
-  ): Promise<ExecuteReturnJsonResponse> {
+  ): Promise<ExecuteReturnJsonResponse | Buffer> {
     const program = _program ?? body?._program
     return executeReturnJson(request, program!)
   }
@@ -96,7 +96,7 @@ export class STPController {
 const executeReturnRaw = async (
   req: express.Request,
   _program: string
-): Promise<string> => {
+): Promise<string | Buffer> => {
   const query = req.query as ExecutionVars
   const sasCodePath =
     path
@@ -113,7 +113,11 @@ const executeReturnRaw = async (
 
     req.res?.set(httpHeaders)
 
-    return result as string
+    if (result instanceof Buffer) {
+      ;(req as any).sasHeaders = httpHeaders
+    }
+
+    return result
   } catch (err: any) {
     throw {
       code: 400,
@@ -127,7 +131,7 @@ const executeReturnRaw = async (
 const executeReturnJson = async (
   req: any,
   _program: string
-): Promise<ExecuteReturnJsonResponse> => {
+): Promise<ExecuteReturnJsonResponse | Buffer> => {
   const sasCodePath =
     path
       .join(getTmpFilesFolderPath(), _program)
@@ -145,6 +149,11 @@ const executeReturnJson = async (
         true
       )) as ExecuteReturnJson
 
+    if (webout instanceof Buffer) {
+      ;(req as any).sasHeaders = httpHeaders
+      return webout
+    }
+
     return {
       status: 'success',
       _webout: webout,
diff --git a/api/src/routes/api/code.ts b/api/src/routes/api/code.ts
index fb751b5..efeaccd 100644
--- a/api/src/routes/api/code.ts
+++ b/api/src/routes/api/code.ts
@@ -12,6 +12,12 @@ runRouter.post('/execute', async (req, res) => {
 
   try {
     const response = await controller.executeSASCode(req, body)
+
+    if (response instanceof Buffer) {
+      res.writeHead(200, (req as any).sasHeaders)
+      return res.end(response)
+    }
+
     res.send(response)
   } catch (err: any) {
     const statusCode = err.code
diff --git a/api/src/routes/api/stp.ts b/api/src/routes/api/stp.ts
index 9879a7c..425208e 100644
--- a/api/src/routes/api/stp.ts
+++ b/api/src/routes/api/stp.ts
@@ -14,6 +14,12 @@ stpRouter.get('/execute', async (req, res) => {
 
   try {
     const response = await controller.executeReturnRaw(req, query._program)
+
+    if (response instanceof Buffer) {
+      res.writeHead(200, (req as any).sasHeaders)
+      return res.end(response)
+    }
+
     res.send(response)
   } catch (err: any) {
     const statusCode = err.code
@@ -40,6 +46,12 @@ stpRouter.post(
         body,
         query?._program
       )
+
+      if (response instanceof Buffer) {
+        res.writeHead(200, (req as any).sasHeaders)
+        return res.end(response)
+      }
+
       res.send(response)
     } catch (err: any) {
       const statusCode = err.code
diff --git a/api/src/utils/extractHeaders.ts b/api/src/utils/extractHeaders.ts
index e3812f0..bf64a14 100644
--- a/api/src/utils/extractHeaders.ts
+++ b/api/src/utils/extractHeaders.ts
@@ -4,20 +4,20 @@ export interface HTTPHeaders {
   [key: string]: string
 }
 
-export const extractHeaders = (content: string): HTTPHeaders => {
+export const extractHeaders = (content?: string): HTTPHeaders => {
   const headersObj: HTTPHeaders = {}
   const headersArr = content
-    .split('\n')
+    ?.split('\n')
     .map((line) => line.trim())
     .filter((line) => !!line)
 
-  headersArr.forEach((headerStr) => {
+  headersArr?.forEach((headerStr) => {
     const [key, value] = headerStr.split(':').map((data) => data.trim())
 
     if (value && headerUtils.validateHeader(key, value)) {
-      headersObj[key] = value
+      headersObj[key.toLowerCase()] = value
     } else {
-      delete headersObj[key]
+      delete headersObj[key.toLowerCase()]
     }
   })
 
diff --git a/api/src/utils/specs/extractHeaders.spec.ts b/api/src/utils/specs/extractHeaders.spec.ts
index 4e6e467..9d29f04 100644
--- a/api/src/utils/specs/extractHeaders.spec.ts
+++ b/api/src/utils/specs/extractHeaders.spec.ts
@@ -12,8 +12,8 @@ describe('extractHeaders', () => {
     `)
 
     expect(headers).toEqual({
-      'Content-type': 'application/zip',
-      'Cache-Control': 'public, max-age=1000'
+      'content-type': 'application/zip',
+      'cache-control': 'public, max-age=1000'
     })
   })
 
@@ -25,7 +25,7 @@ describe('extractHeaders', () => {
       Content-type:    
     `)
 
-    expect(headers).toEqual({ 'Cache-Control': 'public, max-age=1000' })
+    expect(headers).toEqual({ 'cache-control': 'public, max-age=1000' })
   })
 
   it('should return only valid http headers', () => {
@@ -37,4 +37,16 @@ describe('extractHeaders', () => {
 
     expect(headers).toEqual({})
   })
+
+  it('should return http headers if empty', () => {
+    const headers = extractHeaders('')
+
+    expect(headers).toEqual({})
+  })
+
+  it('should return http headers if not provided', () => {
+    const headers = extractHeaders()
+
+    expect(headers).toEqual({})
+  })
 })