---
title: Developer Toolbox — Free Client-Side Developer Tools | Stanza
description: Free browser tools for payments, logistics, and GS1 data: IBAN checker and generator, container check digits, air waybill validation, and GTIN calculators. No sign-up, no API key.
canonical: https://stanzaapi.com/toolbox
---

[Home](/)/[API Directory](/tools/)/Developer Toolbox

 FreeNo sign-upRuns in your browser

# Developer Toolbox

Free client-side tools for payments, logistics, and GS1 data. Every tool runs in your browser, needs no API key, and never sends your values to a server.

## Free tools

[IBAN Checker: Validate IBAN Numbers and MOD-97 Checksum](/tools/iban-validator/checker)

An IBAN checker validates an International Bank Account Number against the length and structure rules for its country and the ISO 7064 MOD-97-10 checksum, then breaks the number into its country, check-digit, bank, branch, and account parts.

[Open tool →](/tools/iban-validator/checker)[API →](/tools/iban-validator/)

[IBAN Generator: Create Valid Test IBANs for Any Country](/tools/iban-validator/generator)

An IBAN generator creates structurally valid, checksum-correct bank account numbers for software testing. Each value matches the ISO 13616 country format and passes the ISO 7064 MOD-97 check, but it is not tied to a real account and cannot receive payments.

[Open tool →](/tools/iban-validator/generator)[API →](/tools/iban-validator/)

[Container Check Digit Calculator (ISO 6346)](/tools/container-validator/check-digit-calculator)

A container check digit calculator computes the 11th character of an ISO 6346 container number from the three-letter owner code, the equipment category letter, and the six-digit serial number.

[Open tool →](/tools/container-validator/check-digit-calculator)[API →](/tools/container-validator/)

[Air Waybill Validator: Check an 11-Digit AWB Number](/tools/iata-validator/air-waybill-validator)

An air waybill validator checks the structure of an 11-digit IATA air waybill number and verifies that its final digit equals the seven-digit serial number modulo 7.

[Open tool →](/tools/iata-validator/air-waybill-validator)[API →](/tools/iata-validator/)

[GTIN Check Digit Calculator (GTIN-8, GTIN-12, GTIN-13, GTIN-14)](/tools/gs1-decoder/gtin-check-digit-calculator)

A GTIN check digit calculator computes the final digit of a GTIN-8, GTIN-12, GTIN-13, or GTIN-14 by applying the GS1 modulo-10 algorithm to the preceding digits.

[Open tool →](/tools/gs1-decoder/gtin-check-digit-calculator)[API →](/tools/gs1-decoder/)

## Frequently Asked Questions

Do the browser tools require an API key or account?

No. Every tool in the toolbox runs entirely in your browser with no sign-up and no API key. Open a page, use it, and close it.

Is the data I enter sent to Stanza?

No. The engines are embedded in each page and execute locally in JavaScript. Values you type or generate never leave your device.

When should I use the API instead of the free tools?

The browser tools are built for one-off checks. The Stanza APIs add batch processing, typed JSON envelopes, published rate limits, and an uptime SLA for production integrations.

Are generated test values safe for production?

No. Generated IBANs and check digits are valid for testing, but they are not real accounts or shipments. Never use test values in live transactions.

Useful?

Bookmark it for the next check, or pass it to someone who works with these numbers.

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Press Ctrl+D to bookmark this page. Installed as an app, the tools also work offline.