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# PDF/A with fpdf2
_New in [:octicons-tag-24: 2.8.5](https://github.com/py-pdf/fpdf2/blob/master/CHANGELOG.md)_
## What is PDF/A
**PDF/A** is the ISO standard for long-term archiving of PDFs. It restricts features that aren’t stable for preservation (e.g., JavaScript, encryption, multimedia) and **requires self-containment** (fonts embedded, color spaces defined, predictable rendering).
---
## Choosing a PDF/A Profile
| Profile | Description | Actions Allowed | Actions Disallowed | Recommended Use Cases |
| ------------ | ----------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------- |
| **PDF/A-1B** | “B” = *Basic visual appearance*. Earliest profile, **based on PDF 1.4**; stricter feature set (no transparency/layers). | ✅ Embedding fonts<br>✅ JPEG/PNG/TIFF images (PDF 1.4 codecs)<br>✅ Digital signatures<br>✅ ICC OutputIntent for color management | ❌ Encryption<br>❌ JavaScript<br>❌ Multimedia (audio/video)<br>❌ External content dependencies<br>❌ Transparency (blend modes/soft masks)<br>❌ Layers (OCGs)<br>❌ JPEG2000 images<br>❌ Embedded file attachments | **Legacy/long-term archives** needing maximum compatibility; **scanned documents** where appearance is paramount. |
| **PDF/A-2B** | “B” = *Basic visual appearance*. Ensures documents can be reliably rendered visually. Based on PDF 1.7. | ✅ Embedding fonts<br>✅ JPEG/JPEG2000/PNG/TIFF images<br>✅ Transparency<br>✅ Layers (OCGs)<br>✅ Digital signatures | ❌ Encryption<br>❌ JavaScript<br>❌ Multimedia (audio/video)<br>❌ External content dependencies | **Scanned documents** where only appearance must be preserved (invoices, contracts for viewing). |
| **PDF/A-2U** | Adds “U” = *Unicode text mapping*. Same as 2B + text must be Unicode-mapped for reliable search/extract. | ✅ Same as 2B<br>✅ Text extractable & searchable | ❌ Same restrictions as 2B | **Searchable archives** (legal texts, regulations, scientific articles). |
| **PDF/A-3B** | Like 2B, **plus** allows embedding *arbitrary files* as attachments (XML, CSV, DOCX, etc.). | ✅ Same as 2B<br>✅ Embed external files **inside** the PDF | ❌ Encryption<br>❌ JavaScript<br>❌ Multimedia | **Compound documents** (e-invoices with XML, submissions needing source data). |
| **PDF/A-3U** | 3B + Unicode requirement for text. | ✅ Same as 3B + searchable text | ❌ Same as 3B | **Archival packages** that need attachments + searchable text. |
| **PDF/A-4** | Based on PDF 2.0 (ISO 32000-2). Simplified model; no A/B/U tiers—modern baseline. | ✅ Unicode text mapping<br>✅ Attachments allowed<br>✅ Transparency, layers, signatures | ❌ Encryption<br>❌ JavaScript<br>❌ Multimedia | **Modern general-purpose archiving** for libraries, government, enterprises. |
| **PDF/A-4E** | “E” = *Engineering*. Tailored for engineering/CAD workflows; supports 3D model containers. | ✅ Same as 4<br>✅ Engineering/CAD payloads (e.g., model data) | ❌ Encryption<br>❌ JavaScript<br>❌ Non-archival multimedia | **Engineering & CAD archiving** (technical drawings, 3D models, BOMs). |
| **PDF/A-4F** | “F” = *File attachments*. Focused on embedded companion files. | ✅ Same as 4<br>✅ File attachments emphasized | ❌ Encryption<br>❌ JavaScript<br>❌ Multimedia | **Data-centric bundles** (PDF + XML/CSV/JSON source files). |
---
## How to produce PDF/A with fpdf2
### Pick a profile at construction time
```python
from fpdf import FPDF
from fpdf.enums import DocumentCompliance
pdf = FPDF(enforce_compliance=DocumentCompliance.PDFA_4)
```
* When `enforce_compliance` is set, **fpdf2 actively prevents non-compliant operations** and will raise errors if you try something forbidden for the selected profile.
### Quick example
```python
pdf = FPDF(enforce_compliance=DocumentCompliance.PDFA_4)
pdf.add_page()
pdf.set_font("Helvetica", size=12)
pdf.cell(0, 10, "Modern archival PDF, PDF 2.0 based.")
pdf.output("example-4.pdf")
```
---
## Future: Accessible documents (WCAG/PDF/UA)
To enable PDF/A 2A and 3A compliance FPDF needs to be able to produce accessible documents.
Those features need to be implemented:
* **Tagged PDFs** (logical structure, reading order)
* **Alt text** for images, meaningful link text
* **Color contrast** and keyboard-navigable annotations
|
