What you will need
- A synthetic invoice or form containing no real personal, financial or confidential data
- An explicit list of field names, data types and missing-value rules
- Time to check the output against the document and understand account or billing requirements
Step by step
Define a small output schema
Start with a document ID, date, currency, line items and total, or the equivalent fields for your form. Keep identifiers as text so leading zeros survive. Use null for absent information. Do not ask the model to fill missing facts from context.
Choose a setup you can support
Nanonets and Mindee are account-based candidates with initial credits or a trial. Google Document AI requires a cloud project, API, billing and suitable access roles. Azure Document Intelligence requires an Azure account and subscription. These are not equivalent to an anonymous drag-and-drop utility.
Bound the first experiment
Use one short synthetic sample and read current model, page, credit and retention rules. Azure F0’s researched limits are 500 pages/month, a 4 MB file cap and only the first two pages per PDF/TIFF request. A headline allowance does not mean a longer document is fully processed. Stop before any paid run unless you intend to authorize its cost.
Validate structure and values
Check each required key, type and missing value. Compare dates, decimals, currency and totals directly with the original. Check that a subtotal was not mistaken for the total and that one line item was not merged into another. Flag uncertainty for review rather than silently correcting it.
Decide whether the workflow is useful
Record what was missing, what needed correction and whether the output format fits your next step. Do not route extracted data into payments or other consequential actions automatically. Before using real documents, review permission, provider privacy and retention terms and appropriate access controls.
A small, safe example
Synthetic extraction contract: Return document_id as text, date as YYYY-MM-DD or null, currency as a printed three-letter code or null, and total as a decimal string or null. Example source: “DEMO-0042; 2026-10-01; USD; Total 12.50.” Expected values: DEMO-0042, 2026-10-01, USD, 12.50. If currency is not printed, return null rather than guessing from a symbol.
Limitations to keep in view
- Initial credits, free evaluation tiers and recurring free allowances are different offers; trial-only products do not pass the free-option filter
- Model and language support vary; handwriting, mixed scripts and complex layouts need separate testing
- This guide does not establish extraction accuracy, data-handling suitability or a per-document cost
If the tool doesn't work for you
Enter a small field set manually from the source and have it checked. For recurring high-stakes documents, keep human review until you have tested the exact document types and failure cases.