Performance

All benchmarks run via phpbench on the same machine. phpdftk generates spec-compliant PDFs with proper xref tables, binary comments, and typed trailers.

PDF Generation Time

Library	1 page	5 pages	10 pages	50 pages	100 pages
phpdftk	938 us	1.1 ms	1.2 ms	2.2 ms	3.5 ms
FPDF	432 us	459 us	541 us	833 us	1.2 ms
TCPDF	5.4 ms	5.7 ms	6.3 ms	10.7 ms	16.2 ms
mPDF	12.4 ms	14.7 ms	16.4 ms	33.0 ms	54.4 ms
Dompdf	5.4 ms	7.7 ms	10.4 ms	39.5 ms	88.0 ms

phpdftk is 3-25x faster than TCPDF, mPDF, and Dompdf. It’s within 2x of FPDF (a minimal library with no font embedding, no encryption, no annotations).

Peak Memory

Library	1 page	10 pages	100 pages
phpdftk	5.8 MB	5.9 MB	7.4 MB
FPDF	5.3 MB	5.3 MB	5.3 MB
TCPDF	13.0 MB	13.0 MB	13.0 MB
mPDF	17.8 MB	17.9 MB	18.6 MB
Dompdf	9.5 MB	10.0 MB	16.1 MB

PDF Parsing Performance

Library	1 page	10 pages	100 pages
phpdftk	601 us	867 us	3.8 ms
smalot/pdfparser	871 us	1.1 ms	2.9 ms
setasign/fpdi	953 us	1.5 ms	21.5 ms

What’s being measured

• Generation: create N pages with text content, serialize to PDF bytes
• Memory: peak memory_get_peak_usage(true) during generation
• Parsing: open PDF, extract catalog/info/version, iterate all pages

Conformance validation overhead

Cost of running ISO standard validation during PDF generation (10 pages with embedded TrueType font):

Profile	Time
PDF/A-1b	27.6 ms
PDF/UA-1	25.4 ms
PDF/X-4	26.5 ms
PDF/VT-1	29.4 ms
PDF/X-5g	29.1 ms
ZUGFeRD BASIC	30.8 ms
PDF/mail-1	34.0 ms
PDF/R-1	4.0 ms

Most of the cost is font embedding and OutputIntent setup, not the constraint checking itself.

Spec compliance advantage

phpdftk handles both classic xref tables (20-byte entries per ISO 32000-2 SS7.5.4) and cross-reference streams (PDF 1.5+). Many competitors fail on one or both formats.

Running benchmarks yourself

# Full benchmark suite (generates docs/generated/benchmarks.md)
mise run benchmark

# Single benchmark class
vendor/phpbench/phpbench/phpbench run benchmarks/GeneratePdfBench.php --report=default