diff --git a/apps/server/src/infra/preview-generator/preview-generator.service.spec.ts b/apps/server/src/infra/preview-generator/preview-generator.service.spec.ts
index 016c261b122..6c5a3eb036d 100644
--- a/apps/server/src/infra/preview-generator/preview-generator.service.spec.ts
+++ b/apps/server/src/infra/preview-generator/preview-generator.service.spec.ts
@@ -1,6 +1,7 @@
 import { DeepMocked, createMock } from '@golevelup/ts-jest';
-import { Test, TestingModule } from '@nestjs/testing';
 import { GetFile, S3ClientAdapter } from '@infra/s3-client';
+import { UnprocessableEntityException } from '@nestjs/common';
+import { Test, TestingModule } from '@nestjs/testing';
 import { Logger } from '@src/core/logger';
 import { Readable } from 'node:stream';
 import { PreviewGeneratorService } from './preview-generator.service';
@@ -16,13 +17,13 @@ jest.mock('gm', () => {
 	};
 });
 
-const createFile = (contentRange?: string): GetFile => {
+const createFile = (contentRange?: string, contentType?: string): GetFile => {
 	const text = 'testText';
 	const readable = Readable.from(text);
 
 	const fileResponse = {
 		data: readable,
-		contentType: 'image/jpeg',
+		contentType,
 		contentLength: text.length,
 		contentRange,
 		etag: 'testTag',
@@ -68,76 +69,136 @@ describe('PreviewGeneratorService', () => {
 	});
 
 	describe('generatePreview', () => {
-		const setup = (width = 500) => {
-			const params = {
-				originFilePath: 'file/test.jpeg',
-				previewFilePath: 'preview/text.webp',
-				previewOptions: {
-					format: 'webp',
-					width,
-				},
-			};
-			const originFile = createFile();
-			s3ClientAdapter.get.mockResolvedValueOnce(originFile);
+		describe('WHEN download of original and preview file is successful', () => {
+			describe('WHEN preview is possible', () => {
+				const setup = (width = 500) => {
+					const params = {
+						originFilePath: 'file/test.jpeg',
+						previewFilePath: 'preview/text.webp',
+						previewOptions: {
+							format: 'webp',
+							width,
+						},
+					};
+					const originFile = createFile(undefined, 'image/jpeg');
+					s3ClientAdapter.get.mockResolvedValueOnce(originFile);
 
-			const data = Readable.from('text');
-			streamMock.mockReturnValueOnce(data);
+					const data = Readable.from('text');
+					streamMock.mockReturnValueOnce(data);
 
-			const expectedFileData = {
-				data,
-				mimeType: params.previewOptions.format,
-			};
+					const expectedFileData = {
+						data,
+						mimeType: params.previewOptions.format,
+					};
 
-			return { params, originFile, expectedFileData };
-		};
+					return { params, originFile, expectedFileData };
+				};
 
-		describe('WHEN download of original and preview file is successful', () => {
-			it('should call storageClient get method with originFilePath', async () => {
-				const { params } = setup();
+				it('should call storageClient get method with originFilePath', async () => {
+					const { params } = setup();
 
-				await service.generatePreview(params);
+					await service.generatePreview(params);
 
-				expect(s3ClientAdapter.get).toBeCalledWith(params.originFilePath);
-			});
+					expect(s3ClientAdapter.get).toBeCalledWith(params.originFilePath);
+				});
 
-			it('should call imagemagicks resize method', async () => {
-				const { params } = setup();
+				it('should call imagemagicks resize method', async () => {
+					const { params } = setup();
 
-				await service.generatePreview(params);
+					await service.generatePreview(params);
 
-				expect(resizeMock).toHaveBeenCalledWith(params.previewOptions.width, undefined, '>');
-				expect(resizeMock).toHaveBeenCalledTimes(1);
-			});
+					expect(resizeMock).toHaveBeenCalledWith(params.previewOptions.width, undefined, '>');
+					expect(resizeMock).toHaveBeenCalledTimes(1);
+				});
 
-			it('should call imagemagicks stream method', async () => {
-				const { params } = setup();
+				it('should call imagemagicks stream method', async () => {
+					const { params } = setup();
 
-				await service.generatePreview(params);
+					await service.generatePreview(params);
 
-				expect(streamMock).toHaveBeenCalledWith(params.previewOptions.format);
-				expect(streamMock).toHaveBeenCalledTimes(1);
-			});
+					expect(streamMock).toHaveBeenCalledWith(params.previewOptions.format);
+					expect(streamMock).toHaveBeenCalledTimes(1);
+				});
 
-			it('should call S3ClientAdapters create method', async () => {
-				const { params, expectedFileData } = setup();
+				it('should call S3ClientAdapters create method', async () => {
+					const { params, expectedFileData } = setup();
 
-				await service.generatePreview(params);
+					await service.generatePreview(params);
 
-				expect(s3ClientAdapter.create).toHaveBeenCalledWith(params.previewFilePath, expectedFileData);
-				expect(s3ClientAdapter.create).toHaveBeenCalledTimes(1);
-			});
+					expect(s3ClientAdapter.create).toHaveBeenCalledWith(params.previewFilePath, expectedFileData);
+					expect(s3ClientAdapter.create).toHaveBeenCalledTimes(1);
+				});
 
-			it('should should return values', async () => {
-				const { params } = setup();
-				const expectedValue = { previewFilePath: params.previewFilePath, status: true };
+				it('should should return values', async () => {
+					const { params } = setup();
+					const expectedValue = { previewFilePath: params.previewFilePath, status: true };
 
-				const result = await service.generatePreview(params);
+					const result = await service.generatePreview(params);
 
-				expect(result).toEqual(expectedValue);
+					expect(result).toEqual(expectedValue);
+				});
+			});
+
+			describe('WHEN preview is not possible', () => {
+				const setup = (mimeType?: string, width = 500) => {
+					const params = {
+						originFilePath: 'file/test.jpeg',
+						previewFilePath: 'preview/text.webp',
+						previewOptions: {
+							format: 'webp',
+							width,
+						},
+					};
+					const originFile = createFile(undefined, mimeType);
+					s3ClientAdapter.get.mockResolvedValueOnce(originFile);
+
+					return { params, originFile };
+				};
+
+				describe('WHEN mimeType is undefined', () => {
+					it('should throw UnprocessableEntityException', async () => {
+						const { params } = setup();
+
+						const error = new UnprocessableEntityException();
+						await expect(service.generatePreview(params)).rejects.toThrowError(error);
+					});
+				});
+
+				describe('WHEN mimeType is text/plain ', () => {
+					it('should throw UnprocessableEntityException', async () => {
+						const { params } = setup('text/plain');
+
+						const error = new UnprocessableEntityException();
+						await expect(service.generatePreview(params)).rejects.toThrowError(error);
+					});
+				});
 			});
 		});
 
 		describe('WHEN previewParams.width not set', () => {
+			const setup = (width = 500) => {
+				const params = {
+					originFilePath: 'file/test.jpeg',
+					previewFilePath: 'preview/text.webp',
+					previewOptions: {
+						format: 'webp',
+						width,
+					},
+				};
+				const originFile = createFile(undefined, 'image/jpeg');
+				s3ClientAdapter.get.mockResolvedValueOnce(originFile);
+
+				const data = Readable.from('text');
+				streamMock.mockReturnValueOnce(data);
+
+				const expectedFileData = {
+					data,
+					mimeType: params.previewOptions.format,
+				};
+
+				return { params, originFile, expectedFileData };
+			};
+
 			it('should not call imagemagicks resize method', async () => {
 				const { params } = setup(0);
 
diff --git a/apps/server/src/infra/preview-generator/preview-generator.service.ts b/apps/server/src/infra/preview-generator/preview-generator.service.ts
index 795fd0f4ddf..d9c2135ceb0 100644
--- a/apps/server/src/infra/preview-generator/preview-generator.service.ts
+++ b/apps/server/src/infra/preview-generator/preview-generator.service.ts
@@ -1,5 +1,5 @@
 import { GetFile, S3ClientAdapter } from '@infra/s3-client';
-import { Injectable } from '@nestjs/common';
+import { Injectable, UnprocessableEntityException } from '@nestjs/common';
 import { Logger } from '@src/core/logger';
 import { subClass } from 'gm';
 import { PassThrough } from 'stream';
@@ -20,6 +20,9 @@ export class PreviewGeneratorService {
 		const { originFilePath, previewFilePath, previewOptions } = params;
 
 		const original = await this.downloadOriginFile(originFilePath);
+
+		this.checkIfPreviewPossible(original, params);
+
 		const preview = this.resizeAndConvert(original, previewOptions);
 
 		const file = PreviewGeneratorBuilder.buildFile(preview, params.previewOptions);
@@ -34,6 +37,16 @@ export class PreviewGeneratorService {
 		};
 	}
 
+	private checkIfPreviewPossible(original: GetFile, params: PreviewFileOptions): void | UnprocessableEntityException {
+		const isPreviewPossible =
+			original.contentType && Object.values<string>(PreviewInputMimeTypes).includes(original.contentType);
+
+		if (!isPreviewPossible) {
+			this.logger.warning(new PreviewActionsLoggable('PreviewGeneratorService.previewNotPossible', params));
+			throw new UnprocessableEntityException();
+		}
+	}
+
 	private async downloadOriginFile(pathToFile: string): Promise<GetFile> {
 		const file = await this.storageClient.get(pathToFile);