AFP file validator
Drop an AFP / MO:DCA file for an instant structural preflight — framing, Begin/End nesting, the document envelope, page count, and referenced resources, each with a byte offset. It runs entirely on your machine.
Drop an AFP file here
or browse · .afp / MO:DCA ·
🔒 Your file never leaves your browser — it is parsed entirely on your machine. No upload, no server, nothing sent.
What this checks
An AFP file is a sequence of MO:DCA structured fields. Each begins with a 0x5A introducer, a two-byte length, and a three-byte identifier (SFID). This validator walks that sequence and reports:
- Framing — every field starts with
0x5A, declares a valid in-bounds length, and the stream ends cleanly (no truncation or trailing bytes). - Begin/End nesting — every Begin (BDT, BPG, BAG, BNG, BRG, BR…) has a matching End in last-opened-first order.
- Document envelope — exactly one BDT…EDT wrapping the document, with pages nested inside.
- Inventory — the structured-field tree with names, byte offsets, and lengths; the page count; and the referenced resource names.
What is AFP / MO:DCA preflight?
Preflighting an AFP document is the print/CCM equivalent of preflighting a PDF: confirm the structure is well-formed and complete before it hits the print stream. This free tool is the structural first pass — what is AFP?. Resource resolution, visual rendering, deep validation, batch/CI, and PDF/PCL are Preflight Pro.
FAQ
Is my AFP file uploaded anywhere?
No. The file is read and parsed entirely in your browser — there is no upload endpoint and nothing about the file is sent to any server or third party. AFP documents routinely contain customer PII, so the validator is built to never touch the network with your data.
What does the free validator check?
The MO:DCA structured-field framing (every field starts with 0x5A and stays in bounds, the stream ends cleanly), Begin/End pairing and nesting via a stack, exactly one BDT…EDT document envelope, the page count (BPG), referenced resource names (MCF/IPO/IPS/IOB/IMM), and malformed or truncated fields — each reported with a byte offset and a PASS / WARN / FAIL severity.
What is AFP / MO:DCA preflight?
AFP (Advanced Function Presentation) documents are a sequence of MO:DCA structured fields — the print/CCM equivalent of preflighting a PDF. Preflight checks that those structures are well-formed and complete before a document reaches the print stream, catching truncation, broken nesting, and missing envelopes early.
What does Preflight Pro add over this?
Server-side deep validation, resource resolution and availability checking, visual rendering and regression diff, batch and CI processing, PDF and PCL support, and an API. This free tool is the structural first pass; Pro is the full preflight.
Why are some fields shown as “unknown”?
An unrecognized structured-field identifier is a warning, not an error — it is still counted and inventoried. Preflight Pro validates the full MO:DCA set; this free tool names the common IS/3 subset and passes the rest through honestly.