diff --git a/src/adapter/bun/handler.ts b/src/adapter/bun/handler.ts
index a61ec695..d1f56579 100644
--- a/src/adapter/bun/handler.ts
+++ b/src/adapter/bun/handler.ts
@@ -38,13 +38,13 @@ export const mapResponse = (
 				return Response.json(response, set as any)
 
 			case 'ElysiaFile':
-				return handleFile((response as ElysiaFile).value as File, set)
+				return handleFile((response as ElysiaFile).value as File, set, request)
 
 			case 'File':
-				return handleFile(response as File, set)
+				return handleFile(response as File, set, request)
 
 			case 'Blob':
-				return handleFile(response as Blob, set)
+				return handleFile(response as Blob, set, request)
 
 			case 'ElysiaCustomStatusResponse':
 				set.status = (response as ElysiaCustomStatusResponse<200>).code
@@ -175,13 +175,13 @@ export const mapEarlyResponse = (
 				return Response.json(response, set as any)
 
 			case 'ElysiaFile':
-				return handleFile((response as ElysiaFile).value as File, set)
+				return handleFile((response as ElysiaFile).value as File, set, request)
 
 			case 'File':
-				return handleFile(response as File, set)
+				return handleFile(response as File, set, request)
 
 			case 'Blob':
-				return handleFile(response as File | Blob, set)
+				return handleFile(response as File | Blob, set, request)
 
 			case 'ElysiaCustomStatusResponse':
 				set.status = (response as ElysiaCustomStatusResponse<200>).code
@@ -289,13 +289,13 @@ export const mapEarlyResponse = (
 				return Response.json(response, set as any)
 
 			case 'ElysiaFile':
-				return handleFile((response as ElysiaFile).value as File, set)
+				return handleFile((response as ElysiaFile).value as File, set, request)
 
 			case 'File':
-				return handleFile(response as File, set)
+				return handleFile(response as File, set, request)
 
 			case 'Blob':
-				return handleFile(response as File | Blob, set)
+				return handleFile(response as File | Blob, set, request)
 
 			case 'ElysiaCustomStatusResponse':
 				set.status = (response as ElysiaCustomStatusResponse<200>).code
@@ -405,13 +405,13 @@ export const mapCompactResponse = (
 			return Response.json(response)
 
 		case 'ElysiaFile':
-			return handleFile((response as ElysiaFile).value as File)
+			return handleFile((response as ElysiaFile).value as File, undefined, request)
 
 		case 'File':
-			return handleFile(response as File)
+			return handleFile(response as File, undefined, request)
 
 		case 'Blob':
-			return handleFile(response as File | Blob)
+			return handleFile(response as File | Blob, undefined, request)
 
 		case 'ElysiaCustomStatusResponse':
 			return mapResponse(
diff --git a/src/adapter/utils.ts b/src/adapter/utils.ts
index 007f0578..19783fe7 100644
--- a/src/adapter/utils.ts
+++ b/src/adapter/utils.ts
@@ -7,12 +7,75 @@ import { isBun } from '../universal/utils'
 
 export const handleFile = (
 	response: File | Blob,
-	set?: Context['set']
+	set?: Context['set'],
+	request?: Request
 ): Response => {
 	if (!isBun && response instanceof Promise)
-		return response.then((res) => handleFile(res, set)) as any
+		return response.then((res) => handleFile(res, set, request)) as any
 
 	const size = response.size
+
+	const rangeHeader = request?.headers.get('range')
+	if (rangeHeader) {
+		const match = /bytes=(\d*)-(\d*)/.exec(rangeHeader)
+		if (match) {
+			if (!match[1] && !match[2])
+				return new Response(null, {
+					status: 416,
+					headers: mergeHeaders(
+						new Headers({ 'content-range': `bytes */${size}` }),
+						set?.headers ?? {}
+					)
+				})
+
+			let start: number
+			let end: number
+
+			if (!match[1] && match[2]) {
+				const suffix = parseInt(match[2])
+				start = Math.max(0, size - suffix)
+				end = size - 1
+			} else {
+				start = match[1] ? parseInt(match[1]) : 0
+				end = match[2]
+					? Math.min(parseInt(match[2]), size - 1)
+					: size - 1
+			}
+
+			if (start >= size || start > end) {
+				return new Response(null, {
+					status: 416,
+					headers: mergeHeaders(
+						new Headers({ 'content-range': `bytes */${size}` }),
+						set?.headers ?? {}
+					)
+				})
+			}
+
+			const contentLength = end - start + 1
+			const rangeHeaders = new Headers({
+				'accept-ranges': 'bytes',
+				'content-range': `bytes ${start}-${end}/${size}`,
+				'content-length': String(contentLength)
+			})
+
+			// Blob.slice() exists at runtime but is absent from the ESNext lib typings
+			// (no DOM lib). Cast through unknown to the minimal interface we need.
+			// Pass response.type as third arg so the sliced blob preserves MIME type.
+			return new Response(
+				(
+					response as unknown as {
+						slice(start: number, end: number, contentType?: string): Blob
+					}
+				).slice(start, end + 1, response.type),
+				{
+					status: 206,
+					headers: mergeHeaders(rangeHeaders, set?.headers ?? {})
+				}
+			)
+		}
+	}
+
 	const immutable =
 		set &&
 		(set.status === 206 ||
diff --git a/src/adapter/web-standard/handler.ts b/src/adapter/web-standard/handler.ts
index 9dc90ed3..2e057cb1 100644
--- a/src/adapter/web-standard/handler.ts
+++ b/src/adapter/web-standard/handler.ts
@@ -19,7 +19,8 @@ const handleElysiaFile = (
 	file: ElysiaFile,
 	set: Context['set'] = {
 		headers: {}
-	}
+	},
+	request?: Request
 ) => {
 	const path = file.path
 	const contentType =
@@ -42,10 +43,10 @@ const handleElysiaFile = (
 				set.headers['content-length'] = size
 			}
 
-			return handleFile(file.value as any, set)
+			return handleFile(file.value as any, set, request)
 		}) as any
 
-	return handleFile(file.value as any, set)
+	return handleFile(file.value as any, set, request)
 }
 
 export const mapResponse = (
@@ -71,13 +72,13 @@ export const mapResponse = (
 				return new Response(JSON.stringify(response), set as any)
 
 			case 'ElysiaFile':
-				return handleElysiaFile(response as ElysiaFile, set)
+				return handleElysiaFile(response as ElysiaFile, set, request)
 
 			case 'File':
-				return handleFile(response as File, set)
+				return handleFile(response as File, set, request)
 
 			case 'Blob':
-				return handleFile(response as Blob, set)
+				return handleFile(response as Blob, set, request)
 
 			case 'ElysiaCustomStatusResponse':
 				set.status = (response as ElysiaCustomStatusResponse<200>).code
@@ -225,13 +226,13 @@ export const mapEarlyResponse = (
 				return new Response(JSON.stringify(response), set as any)
 
 			case 'ElysiaFile':
-				return handleElysiaFile(response as ElysiaFile, set)
+				return handleElysiaFile(response as ElysiaFile, set, request)
 
 			case 'File':
-				return handleFile(response as File, set)
+				return handleFile(response as File, set, request)
 
 			case 'Blob':
-				return handleFile(response as File | Blob, set)
+				return handleFile(response as File | Blob, set, request)
 
 			case 'ElysiaCustomStatusResponse':
 				set.status = (response as ElysiaCustomStatusResponse<200>).code
@@ -356,13 +357,13 @@ export const mapEarlyResponse = (
 				return new Response(JSON.stringify(response), set as any)
 
 			case 'ElysiaFile':
-				return handleElysiaFile(response as ElysiaFile, set)
+				return handleElysiaFile(response as ElysiaFile, set, request)
 
 			case 'File':
-				return handleFile(response as File, set)
+				return handleFile(response as File, set, request)
 
 			case 'Blob':
-				return handleFile(response as File | Blob, set)
+				return handleFile(response as File | Blob, set, request)
 
 			case 'ElysiaCustomStatusResponse':
 				set.status = (response as ElysiaCustomStatusResponse<200>).code
@@ -495,13 +496,13 @@ export const mapCompactResponse = (
 			})
 
 		case 'ElysiaFile':
-			return handleElysiaFile(response as ElysiaFile)
+			return handleElysiaFile(response as ElysiaFile, undefined, request)
 
 		case 'File':
-			return handleFile(response as File)
+			return handleFile(response as File, undefined, request)
 
 		case 'Blob':
-			return handleFile(response as File | Blob)
+			return handleFile(response as File | Blob, undefined, request)
 
 		case 'ElysiaCustomStatusResponse':
 			return mapResponse(
diff --git a/src/compose.ts b/src/compose.ts
index bf393768..440da3a9 100644
--- a/src/compose.ts
+++ b/src/compose.ts
@@ -894,10 +894,9 @@ export const composeHandler = ({
 		return `const _res=${response}` + after + `return _res`
 	}
 
-	const mapResponseContext =
-		maybeStream && adapter.mapResponseContext
-			? `,${adapter.mapResponseContext}`
-			: ''
+	const mapResponseContext = adapter.mapResponseContext
+		? `,${adapter.mapResponseContext}`
+		: ''
 
 	if (hasTrace || inference.route) fnLiteral += `c.route=\`${path}\`\n`
 	if (hasTrace || hooks.afterResponse?.length)
diff --git a/test/response/range.test.ts b/test/response/range.test.ts
new file mode 100644
index 00000000..4a7b63dc
--- /dev/null
+++ b/test/response/range.test.ts
@@ -0,0 +1,82 @@
+import { describe, expect, it } from 'bun:test'
+
+import { Elysia } from '../../src'
+import { req } from '../utils'
+
+// Regression test for https://github.com/elysiajs/elysia/issues/1790
+// Range header was ignored; always returned bytes 0-N/N instead of the requested slice.
+describe('Range header', () => {
+	const content = '12345'
+	const app = new Elysia().get('/file', () => new Blob([content]))
+
+	it('returns full file without Range header', async () => {
+		const res = await app.handle(req('/file'))
+		expect(res.status).toBe(200)
+		expect(await res.text()).toBe(content)
+	})
+
+	it('handles bytes=start- (open-ended range)', async () => {
+		const res = await app.handle(
+			req('/file', { headers: { range: 'bytes=3-' } })
+		)
+		expect(res.status).toBe(206)
+		expect(res.headers.get('content-range')).toBe('bytes 3-4/5')
+		expect(res.headers.get('content-length')).toBe('2')
+		expect(await res.text()).toBe('45')
+	})
+
+	it('handles bytes=start-end (bounded range)', async () => {
+		const res = await app.handle(
+			req('/file', { headers: { range: 'bytes=1-3' } })
+		)
+		expect(res.status).toBe(206)
+		expect(res.headers.get('content-range')).toBe('bytes 1-3/5')
+		expect(res.headers.get('content-length')).toBe('3')
+		expect(await res.text()).toBe('234')
+	})
+
+	it('handles bytes=-suffix (last N bytes)', async () => {
+		const res = await app.handle(
+			req('/file', { headers: { range: 'bytes=-2' } })
+		)
+		expect(res.status).toBe(206)
+		expect(res.headers.get('content-range')).toBe('bytes 3-4/5')
+		expect(res.headers.get('content-length')).toBe('2')
+		expect(await res.text()).toBe('45')
+	})
+
+	it('clamps end beyond file size to last byte', async () => {
+		const res = await app.handle(
+			req('/file', { headers: { range: 'bytes=2-999' } })
+		)
+		expect(res.status).toBe(206)
+		expect(res.headers.get('content-range')).toBe('bytes 2-4/5')
+		expect(await res.text()).toBe('345')
+	})
+
+	it('returns 416 when start is out of range', async () => {
+		const res = await app.handle(
+			req('/file', { headers: { range: 'bytes=99-' } })
+		)
+		expect(res.status).toBe(416)
+		expect(res.headers.get('content-range')).toBe('bytes */5')
+	})
+
+	it('returns 416 for invalid "bytes=-" (both positions empty)', async () => {
+		const res = await app.handle(
+			req('/file', { headers: { range: 'bytes=-' } })
+		)
+		expect(res.status).toBe(416)
+		expect(res.headers.get('content-range')).toBe('bytes */5')
+	})
+
+	it('ignores subsequent ranges in multi-range requests, uses first range only', async () => {
+		// Multi-range (e.g. bytes=0-1,3-4) is not supported; only the first range is applied.
+		const res = await app.handle(
+			req('/file', { headers: { range: 'bytes=0-1,3-4' } })
+		)
+		expect(res.status).toBe(206)
+		expect(res.headers.get('content-range')).toBe('bytes 0-1/5')
+		expect(await res.text()).toBe('12')
+	})
+})