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Architecture Analysis

Why LLMs Can't Replace Document Extraction APIs

ChatGPT can read a document. It can't build a production pipeline.

DimensionWhen to use LLMs directlyDocDigitizer
Scanned documentsVision models struggle below 200 DPI. No OCR.Dedicated OCR. Handles 75 DPI+, handwriting.
Multi-page documentsContext window limits. Truncation loses data.No page limit. Cross-page context preservation.
Structured outputFields hallucinated/renamed/omitted.Schema-validated. No hallucinations.
Multi-document packetsTreats as one. Boundaries not detected.Auto boundary detection, per-doc extraction.
Rate limitsCustom retry infrastructure needed.Built-in retry, 99.9% SLA.
Cost predictability40-page contract = 80K tokens. Costs spike.Fixed credit per document. Predictable.
Latency30–90 seconds for complex docs.2–8 seconds synchronous.
GDPRUS LLM provider. Requires legal review.EU processing by default. No retention.
Confidence scoresNo field-level confidence.Per-field confidence scores.
Engineering effort190–320 hours (€19K–€32K)9–10 hours + API credits

Honest Assessment

When to use LLMs directly
Need to summarise/analyse, not extract structured fields
Building one-off internal tool, not production pipeline
Volume low (<100/month) and accuracy flexible
Prototyping to validate extraction is worth building
When to choose DocDigitizer
Need structured JSON fields in production
Volume, reliability, cost predictability non-negotiable
Documents include scans, low-quality, multi-page
GDPR compliance requires EU processing
Need audit trails and per-field confidence

The developer experience

DocDigitizer
from docdigitizer import DocDigitizer
client = DocDigitizer("dd-YOUR_KEY")
result = client.extract("invoice.pdf")
# 3 lines. Includes OCR, validation, audit trail.
Alternative
LLM DIY: PDF encoding + schema validators + retry decorators + rate limits + token counting + cost monitoring + audit logging + multi-page chunking. 200+ lines, 190–320 hours.

Can I use DocDigitizer with my LLM agent?

Yes, recommended. DocDigitizer extracts clean JSON, agent receives structured data. Reduces tokens 10x.

Aren't vision models good enough now?

Reliable on clean single-page docs. Failures on scans, rotated pages, multi-column layouts, tables = 15–40% of enterprise volumes.

Try it before you decide.

50 free credits. No signup required for the first extraction.

Questions? → Talk to Us