100% in your browser

The reflex of pros and small projects

46 free online tools.
Four universes, one place.

Invoicing, PDFs, home projects and developer shortcuts — calculators, validators and converters that run 100% in your browser. Built by Flexina: nothing you type ever leaves your device.

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0118 toolsFor businessDecide with confidenceInvoicing, payments, margins and the everyday obligations of running a business.Explore the tools 0211 toolsDocumentsConvert without frictionPDFs, images and files that are ready to share or to archive.Explore the tools 035 toolsHome & projectsMeasure before you actRenovations, energy and practical calculators for the jobs on your list.Explore the tools 0412 toolsTechWork smarterData, code, security and the small shortcuts that save the most time.Explore the tools

All the tools

Every tool on one page

e-Invoicing

04
Peppol BIS 3.0 invoice validatorCheck that a UBL XML respects the EN 16931 and Peppol BIS rules.Factur-X & ZUGFeRD validator / extractorExtract and check the embedded XML of a Factur-X PDF invoice.PDF invoice generator (with payment QR)Create a clean PDF invoice with an embedded EPC payment QR code.UBL / Peppol invoice viewerShow a UBL XML file (a Peppol invoice) in a readable form.

IDs & payments

05
IBAN validatorCheck whether an IBAN account number is valid (modulo 97 key).Company number validator (BCE / SIREN / SIRET)Validate a Belgian company number (BCE) or a French one (SIREN/SIRET).Intracommunity VAT number validatorCheck the format of an EU VAT number (27 countries, BE/FR/LU check key).Belgian structured communication generatorGenerate or check a structured communication (+++xxx/xxxx/xxxxx+++).Payment QR-code generator (EPC)Create a SEPA payment QR code that banking apps scan.

Calculators

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VAT calculator for Belgium and FranceTurn a net amount into gross (TTC) and back, at the rates in force in Belgium and France.Commercial margin calculatorGross margin, margin rate and markup, or the target selling price.Loan calculator & amortisation scheduleMonthly payment, total cost of the loan and the full amortisation table.Rent indexation calculator (Belgium)New rent from the legal Belgian formula, using the health indices.Percentage calculatorX % of Y, a share in %, a change or a discount — every percentage question.Invoice due date & B2B late-payment interestCompute the due date (30 days, end of month…) and the legal late interest.Business-day calculator for Belgium and FranceCount business days between two dates, with public holidays included.Gross / net calculator BelgiumEstimate a net salary from a gross one (ONSS, professional withholding).Gross / net calculator FranceEstimate a net salary from a gross one (contributions, CSG, prelevement à la source).

PDF tools

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Merge PDFsCombine several PDF files into one, in the order you choose.Split a PDF & extract pagesExtract, split or remove pages from a PDF file.Compress a PDFReduce the weight of a PDF, losslessly or by rasterising.PDF to images (PNG / JPEG)Convert the pages of a PDF into PNG or JPEG images.Convert a PDF to Word (.docx)Extract the text of a PDF into an editable Word document.Convert a Word (.docx) to PDFTurn a Word document into a PDF, no software, no account.

Images

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Resize an imageResize one or several images, with cropping to the exact format.Compress an imageReduce the weight of a photo in JPEG or WebP, with a before/after preview.Convert an image (WebP, JPEG, PNG)Convert one or several images between WebP, JPEG and PNG.Remove EXIF metadata from a photoView then erase the hidden data of a photo (GPS, device, date).Favicon generatorCreate a complete favicon set (ICO + PNG) from one image.

Home & everyday

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Electricity consumption calculatorkWh and yearly cost of a device from its power and how it is used.Paint calculatorLitres and tins needed from the area, the coats and the yield.Tiling calculatorNumber of tiles and boxes, with the cutting margin.Rooftop insulation calculatorInsulation thickness needed, thermal resistance R and heating savings.Unit converterConvert lengths, masses, volumes, temperatures, data and more.

Developer tools

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JSON formatter / validatorFormat, minify and validate JSON, with the error located.Base64 encoder / decoderEncode or decode text in Base64, with accents and special characters handled correctly.JWT decoderDecode the header and payload of a JWT, with the dates made readable.UUID generatorGenerate one or several random UUID v4 identifiers.SHA-256 / SHA-512 fingerprint calculatorFingerprint (hash) of a text or a file, computed locally.XML formatter / validatorIndent, minify and validate an XML file.Text comparator (diff)Compare two texts and see the lines added and removed.Regular expression testerTest a regex live: matches, groups and replacement.Cron expression parserTranslate a cron expression into plain words and see the next runs.

Misc

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Word and character counterWords, characters, sentences and reading time of a text.Password generatorGenerate strong, random passwords, offline.QR-code generatorCreate a QR code for a link, a text, a contact or a Wi-Fi network.

Our story

Built by Flexina, to protect our clients

Every tool here is the free version of what we build every day for the self-employed and small businesses.

For years, Flexina has supported self-employed professionals and small companies: management, e-invoicing, field-team tracking. Through our exchanges with clients, one finding became clear — a large share of their time goes to small, repetitive tasks: calculating VAT, checking an IBAN, preparing an invoice, converting a document.

Rather than leave our clients to trust any random website, we built the free versions of these tools ourselves and published them here. And we made one demanding choice: everything runs directly in your browser. Your invoice, your payslip, your contract never leave your device — because we know exactly what these documents are worth when something goes wrong.

This site is alive: new tools are added regularly, often at clients’ request. What we cannot charge for, we give away.

100% local

No file and no data is ever sent to a server. You can cut your connection: the tools keep working.

Born from our craft

Every tool reuses a rule, an algorithm or a check we use ourselves for clients in Belgium and France.

Updated regularly

New tools, fixes and improvements added as field needs evolve — the latest version is always online.

A wider ecosystem

Beyond the tools,
the projects that go with them.

Each tool here is the everyday version of something Flexina builds for clients. The free versions are on this site; the paid ones handle the whole flow. Start small, grow into the service when it earns it.

FBusiness managementFlexinaThe management platform built for the self-employed and small companies.PE-invoicingPeppol BoxSend and receive electronic invoices over the Peppol network.FInvoicing in FranceFrance FacturesSimple, compliant invoicing for French professionals.FField teamsFlexina FieldPlan and track the interventions of your teams on site.