Build and transform data
Format, convert, inspect and secure developer data.
50 free online tools
Focused tools to convert, validate, generate and calculate.
Convert, compress, validate, generate and calculate from one fast catalog. OnSubmit groups practical browser-based tools for PDFs, images, text, developer data, test data and everyday calculations.
50 tools6 categoriesLocal processingFast to use
Start with your task
What do you need to do?
Choose a direction, then open the right focused tool without browsing the whole catalog.
Work with files and images
Convert, combine, split or optimize common file formats.
Generate and validate test data
Prepare realistic fixtures without using real personal or banking data.
Calculate and plan across time
Estimate amounts, compare dates and follow time around the world.
Workflows
Find the right group of tools
Useful workflows that connect several tools around the same task.
8 toolsTest dataGenerate identifiers, fake profiles, addresses, banking details and company data to test interfaces without using real personal data.6 toolsBanking test dataPrepare fictitious banking values to test SEPA forms, IBAN/BIC fields, French RIB details, payment methods and billing workflows.7 toolsBusiness invoicingGroup the tools needed to prepare invoice tests, check French company identifiers, calculate VAT and validate French VAT number structure.6 toolsFinance calculatorsEstimate loan payments, VAT, gross/net amounts, salary and French notary fees for invoices, purchases and budget scenarios.7 toolsData convertersConvert, format and compare structured data for APIs, exports, configuration files, documentation and developer integrations.6 toolsSecurity and hashGenerate passwords, calculate SHA hashes, inspect JWTs and prepare .env.example files without exposing production secrets.5 toolsQR codesCreate QR codes for URLs, text, Wi-Fi, vCard, email, phone and SMS, then read or test their content directly in your browser.
Editorial selection
Recommended tools to get started
A short, curated selection covering useful everyday workflows.
France Fake Address GeneratorGenerate coherent synthetic French addresses locally for forms, CRM, checkout and repeatable QA datasets.Open toolIBAN & BIC GeneratorGenerate fictitious IBAN and BIC values by country for banking forms, QA, mockups and fixtures.Open toolSIRET / SIREN ValidatorValidate the length, structure and Luhn key of French SIREN or SIRET numbers.Open toolFrench VAT Generator & ValidatorGenerate a French VAT number from a valid SIREN or SIRET, then check its local format and key.Open toolHEIC to JPGConvert up to 10 HEIC or HEIF photos to JPG locally for iPhone compatibility, web uploads and sharing.Open toolMD5 Hash GeneratorCalculate and compare the MD5 digest of UTF-8 text or local files for checksums, compatibility and legacy workflows.Open toolTimezone ConverterCompare a date and time across Paris, London, New York, San Francisco, Tokyo, Sydney and UTC.Open toolQR Code GeneratorCreate static QR codes for URLs, text, Wi-Fi, vCard, email, phone and SMS, then export PNG or SVG.Open tool
Why OnSubmit
Simple tools that open fast and stay useful
Immediate access
Open a tool, paste content or select files, then copy the result.
Browser-first
Compatible tasks run directly on your device to keep short workflows short.
Explicit limits
Each tool states whether the result is generated, locally validated, converted or calculated, and when an official source is still required.
FAQ
Frequently asked questions
Are files sent to a server?
Compatible tools process data directly in the browser. If a tool requires external processing, the page should make that clear before use.
What is the difference between generating and validating data?
A generator creates synthetic test data. A validator checks format or checksum rules without proving that the value exists in the real world.
Do I need an account?
No. Public OnSubmit tools are free to use without signup.