> ## Documentation Index > Fetch the complete documentation index at: https://docs.pdf.co/llms.txt > Use this file to discover all available pages before exploring further. # Get MD5 Hash of File by URL > Calculate and return MD5 hash of file by url. Commonly used to control if the source document has been changed or not because every little change will cause hash string to differ as well. ## OpenAPI ````yaml /openapi.json post /v1/file/hash openapi: 3.0.1 info: title: PDF.co API description: '' version: '1.0' servers: - url: https://api.pdf.co security: - ApiKeyAuth: [] tags: - name: Extraction - name: Editing - name: PDF Conversion - name: Excel Conversion - name: PDF Merging & Splitting - name: Forms - name: Find & Search - name: Document, File & System - name: Pages - name: Barcodes paths: /v1/file/hash: post: tags: - Document, File & System summary: Get MD5 Hash of File by URL description: >- Calculate and return MD5 hash of file by url. Commonly used to control if the source document has been changed or not because every little change will cause hash string to differ as well. operationId: post_v1_file_hash requestBody: content: application/json: schema: type: object properties: url: allOf: - $ref: '#/components/schemas/url' default: >- pdfco-test-files.s3.us-west-2.amazonaws.compdf-split/sample.pdf httpusername: $ref: '#/components/schemas/httpusername' httppassword: $ref: '#/components/schemas/httppassword' additionalProperties: false required: - url required: false responses: '200': $ref: '#/components/responses/Success' '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' '402': $ref: '#/components/responses/NotEnoughCredits' '403': $ref: '#/components/responses/Forbidden' '404': $ref: '#/components/responses/NotFound' '408': $ref: '#/components/responses/Timeout' '429': $ref: '#/components/responses/TooManyRequests' '441': $ref: '#/components/responses/InvalidPassword' '442': $ref: '#/components/responses/DamagedDocument' '443': $ref: '#/components/responses/PermissionsError' '444': $ref: '#/components/responses/ProfilesParsingError' '445': $ref: '#/components/responses/TimeoutError' '446': $ref: '#/components/responses/MissingFiles' '447': $ref: '#/components/responses/InvalidTemplate' '448': $ref: '#/components/responses/InvalidUrlOrHtml' '449': $ref: '#/components/responses/InvalidIndexRange' '450': $ref: '#/components/responses/InvalidPageRange' '452': $ref: '#/components/responses/InvalidUrl' '454': $ref: '#/components/responses/InvalidParameters' '500': $ref: '#/components/responses/InternalServerError' components: schemas: url: type: string format: uri description: >- URL to the source file [`url` attribute](/api-reference/url-input-and-request-limits). httpusername: type: string description: HTTP auth user name if required to access source URL. httppassword: type: string description: HTTP auth password if required to access source URL. responses: Success: description: Success. content: application/json: schema: type: object properties: status: type: string example: success description: Status of the API response. message: type: string example: Success description: Descriptive message for the response status. url: type: string format: uri example: https://pdf-temp-files.s3.us-west-2.amazonaws.com/output.pdf description: URL to the output file. jobId: type: string example: 6YSZD3U872ZYYFEDMQCQSGEEO8YSF5WA description: Unique identifier for the job. credits: type: integer example: 2 description: Credits used for this operation. remainingCredits: type: integer example: 1480582 description: Credits remaining after this operation. duration: type: integer example: 33 description: Time taken to complete the request, in milliseconds. BadRequest: description: >- Bad request. Typically due to bad input parameters or unreachable input URLs (e.g., access restrictions like login or password). content: application/json: schema: type: object properties: error: type: boolean example: true status: type: integer example: 400 message: type: string example: >- Bad request. Typically due to bad input parameters or unreachable input URLs (e.g., access restrictions like login or password). Unauthorized: description: >- Unauthorized. Authentication is required and has failed or has not yet been provided. content: application/json: schema: type: object properties: error: type: boolean example: true status: type: integer example: 401 message: type: string example: >- Unauthorized. Authentication is required and has failed or has not yet been provided. NotEnoughCredits: description: Not enough credits. content: application/json: schema: type: object properties: error: type: boolean example: true status: type: integer example: 402 message: type: string example: Not enough credits. Forbidden: description: Access forbidden for input URL. content: application/json: schema: type: object properties: error: type: boolean example: true status: type: integer example: 403 message: type: string example: Access forbidden for input URL. NotFound: description: The requested resource could not be found. content: application/json: schema: type: object properties: error: type: boolean example: true status: type: integer example: 404 message: type: string example: The requested resource could not be found. Timeout: description: The server timed out waiting for the request. content: application/json: schema: type: object properties: error: type: boolean example: true status: type: integer example: 408 message: type: string example: The server timed out waiting for the request. TooManyRequests: description: Too many requests in a given time period. content: application/json: schema: type: object properties: error: type: boolean example: true status: type: integer example: 429 message: type: string example: Too many requests in a given time period. InvalidPassword: description: Invalid Password. Password protected document. content: application/json: schema: type: object properties: error: type: boolean example: true status: type: integer example: 441 message: type: string example: Invalid Password. Password protected document. DamagedDocument: description: Input document is damaged or of incorrect type. content: application/json: schema: type: object properties: error: type: boolean example: true status: type: integer example: 442 message: type: string example: Input document is damaged or of incorrect type. PermissionsError: description: >- Permissions. The operation is prohibited by document security settings. You can turn off this check by setting the `profiles` param to `{CheckPermissions: false}`. Important: only use this if you are the owner or have legal permission. content: application/json: schema: type: object properties: error: type: boolean example: true status: type: integer example: 443 message: type: string example: >- Permissions. The operation is prohibited by document security settings. ProfilesParsingError: description: >- Profiles parsing error. Please ensure that the configuration is supported. See `/profiles` samples. content: application/json: schema: type: object properties: error: type: boolean example: true status: type: integer example: 444 message: type: string example: >- Profiles parsing error. Please ensure that the configuration is supported. TimeoutError: description: >- Timeout error. For large documents, use asynchronous mode (`async=true`) and check status via `/job/check`. For many-page files, use the `pages` parameter. content: application/json: schema: type: object properties: error: type: boolean example: true status: type: integer example: 445 message: type: string example: >- Timeout error. For large documents, use asynchronous mode (async=true) and check status via /job/check. MissingFiles: description: Some files required for conversion are missing. content: application/json: schema: type: object properties: error: type: boolean example: true status: type: integer example: 446 message: type: string example: Some files required for conversion are missing. InvalidTemplate: description: Invalid template. content: application/json: schema: type: object properties: error: type: boolean example: true status: type: integer example: 447 message: type: string example: Invalid template. InvalidUrlOrHtml: description: Invalid URL or HTML. Ensure the provided URL is valid and accessible. content: application/json: schema: type: object properties: error: type: boolean example: true status: type: integer example: 448 message: type: string example: >- Invalid URL or HTML. Ensure the provided URL is valid and accessible. InvalidIndexRange: description: >- Invalid index range. Page index is out of range. Use `/pdf/info` to get page count. First page is `0`. content: application/json: schema: type: object properties: error: type: boolean example: true status: type: integer example: 449 message: type: string example: Invalid index range. Page index is out of range. InvalidPageRange: description: Invalid page range specified. content: application/json: schema: type: object properties: error: type: boolean example: true status: type: integer example: 450 message: type: string example: Invalid page range specified. InvalidUrl: description: Invalid URL. content: application/json: schema: type: object properties: error: type: boolean example: true status: type: integer example: 452 message: type: string example: Invalid URL. InvalidParameters: description: Invalid parameters. content: application/json: schema: type: object properties: error: type: boolean example: true status: type: integer example: 454 message: type: string example: Invalid parameters. InternalServerError: description: Something went wrong. Please try again or contact support. content: application/json: schema: type: object properties: error: type: boolean example: true status: type: integer example: 500 message: type: string example: Something went wrong. Please try again or contact support. securitySchemes: ApiKeyAuth: type: apiKey in: header name: x-api-key ````