Evals / pdf / Read a PDF

Compare two versions

Which pages differ between paper.pdf and paper-stamped.pdf? Write the page numbers to pages.txt, one per line.

hardmulti-stepdeft pdf compare

The task

The reference answer shows the job can be done with deft. It is not an agent run.

(none)

Input

paper-stamped.pdf 936.3 KB · 14 pages
Page 1Page 2Page 3
paper.pdf 992.5 KB · 14 pages
Page 1Page 2Page 3

Reference output



How a result is judged (1 check)
  • python: code = "assert open('pages.txt').read().split() == ['3']"


Runs
CodexWithout deftPassed2026-11-07


Time
30s
New tokens
9.1k
Total input
112.4k


Output tokens
1.0k
Commands
7
Failed
1


Trace
  1. I’ll compare the PDFs page by page, then write the differing page numbers to `pages.txt` in the current directory.
  2. ls -la && file paper.pdf paper-stamped.pdf
    output
    total 3872
drwxr-xr-x@    4 user  staff      128 Nov  6 17:16 .
drwx------@ 1713 user  staff    54816 Nov  6 17:16 ..
-rw-r--r--@    1 user  staff   958769 Nov  6 14:58 paper-stamped.pdf
-rw-r--r--@    1 user  staff  1016315 Nov  5 21:11 paper.pdf
paper.pdf:         PDF document, version 1.4, 6 pages
paper-stamped.pdf: PDF document, version 1.5
  3. pdfinfo paper.pdf | head -20; pdfinfo paper-stamped.pdf | head -20; command -v pdftoppm; command -v pdftotext; command -v qpdf (exit 1)
    output
    zsh:1: command not found: pdfinfo
zsh:1: command not found: pdfinfo
  4. python3 - <<'PY'
mods=['fitz','pypdf','PyPDF2','PIL','pdf2image']
for m in mods:
 try:
  x=__import__(m); print(m, getattr(x,'__version__','ok'))
 except Exception as e: print(m, 'NO',e)
PY
    output
    fitz NO No module named 'fitz'
pypdf NO No module named 'pypdf'
PyPDF2 NO No module named 'PyPDF2'
PIL 12.2.0
pdf2image NO No module named 'pdf2image'
  5. which gs mutool pdftocairo magick convert sips swift; python3 - <<'PY'
import importlib.util
print(importlib.util.find_spec('Quartz'))
PY
    output
    /usr/local/bin/gs
mutool not found
pdftocairo not found
magick not found
convert not found
/usr/bin/sips
/usr/bin/swift
None
  6. mkdir -p <tmp> <tmp> && gs -q -dSAFER -dBATCH -dNOPAUSE -sDEVICE=pnggray -r120 -dTextAlphaBits=4 -dGraphicsAlphaBits=4 -sOutputFile=<tmp> paper.pdf && gs -q -dSAFER -dBATCH -dNOPAUSE -sDEVICE=pnggray -r120 -dTextAlphaBits=4 -dGraphicsAlphaBits=4 -sOutputFile=<tmp> paper-stamped.pdf && ls <tmp> <tmp>
    output
    <tmp>
page-001.png
page-002.png
page-003.png
page-004.png
page-005.png
page-006.png
page-007.png
page-008.png
page-009.png
page-010.png
page-011.png
page-012.png
page-013.png
page-014.png

<tmp>
page-001.png
page-002.png
page-003.png
page-004.png
page-005.png
page-006.png
page-007.png
page-008.png
page-009.png
page-010.png
page-011.png
page-012.png
page-013.png
page-014.png
  7. python3 - <<'PY'
from PIL import Image, ImageChops
import os
for i in range(1,15):
 a=Image.open(f'<tmp>').convert('L'); b=Image.open(f'<tmp>').convert('L')
 d=ImageChops.difference(a,b)
 h=d.histogram(); changed=sum(v for j,v in enumerate(h) if j>8)
 print(i, a.size,b.size,changed, d.getbbox())
PY
    output
    1 (1020, 1320) (1020, 1320) 0 None
2 (1020, 1320) (1020, 1320) 0 None
3 (1020, 1320) (1020, 1320) 67653 (93, 228, 889, 1182)
4 (1020, 1320) (1020, 1320) 0 None
5 (1020, 1320) (1020, 1320) 0 None
6 (1020, 1320) (1020, 1320) 0 None
7 (1020, 1320) (1020, 1320) 0 None
8 (1020, 1320) (1020, 1320) 0 None
9 (1020, 1320) (1020, 1320) 0 None
10 (1020, 1320) (1020, 1320) 0 None
11 (1020, 1320) (1020, 1320) 0 None
12 (1020, 1320) (1020, 1320) 0 None
13 (1020, 1320) (1020, 1320) 0 None
14 (1020, 1320) (1020, 1320) 0 None
  8. printf '3\\n' > pages.txt && cat pages.txt
    output
    3
  9. Page 3 differs. I wrote `3` to [pages.txt](pages.txt).
Output
pages.txt 2 B
3

CodexWith deft, skill installedPassedRead the skillUsed deft2026-11-07


Time
16s
New tokens
8.2k
Total input
71.3k


Output tokens
0.5k
Commands
4
Failed
0


Trace
  1. I’ll compare the two PDFs page by page, then write the differing page numbers to `pages.txt` in the current directory.
  2. cat .agents/skills/deft/SKILL.md && rg --files -g 'paper.pdf' -g 'paper-stamped.pdf' -g 'AGENTS.md'
    output
    ---
name: deft
description: "Use deft instead of writing a script for file jobs: PDF merge/split/compress/watermark, image resize/convert/compress, video and audio trim/convert/compress, spreadsheets, Markdown to PDF/HTML, and YouTube downloads and subtitles."
---

# deft

One local command for file jobs. Prefer it over writing Python or shell scripts.

Syntax: `deft <group> <command> [inputs] [-o output] [--options]`

Groups:
- `pdf`: Merge, split, compress, encrypt, forms, OCR, compare, convert
- `image`: Resize, crop, convert, compress, filters, montage, OCR
- `video`: Trim, crop, speed, convert, compress, GIF, frames (ffmpeg)
- `audio`: Convert, trim, merge, fade, speed, tag, normalize (ffmpeg)
- `doc`: Word/ODT/RTF: to text, Markdown, HTML, PDF; find and replace
- `slides`: PowerPoint: extract text, Markdown outline, PDF handout
- `data`: JSON/YAML/TOML/XML: convert, query with jq syntax, merge, diff
- `sheet`: Excel/CSV/ODS tables: filter, sort, join, pivot, convert
- `md`: Markdown to PDF, HTML, Word, EPUB; table of contents
- `html`: HTML to Markdown, text, Word, PDF; screenshots
- `epub`: E-books: info, to text, Markdown and PDF
- `email`: EML files: headers, text, attachments
- `contact`: VCF address books: to and from CSV
- `calendar`: ICS calendars: to and from CSV
- `gps`: GPX and KML tracks: convert, distance and time
- `youtube`: Info, download, audio, subtitles, thumbnail (yt-dlp)
- `file`: Any file: hash, duplicates, batch rename, base64, encoding
- `qr`: Cre
… 756 more characters
  3. I’m using the `deft` file workflow for the PDF comparison. Both input files are present; I’m checking the compare options and will record the differing pages.
  4. deft pdf compare --help
    output
    deft pdf compare - Compare two PDFs: text and pixels

Usage: deft pdf compare <pdf>... [options]
In: pdf (all together, in order)   Out: printed result
--text-only skips rendering. Reports lines added and removed per page.

Options:
  --text-only                  Do not compare the pictures
  --dpi <n>                    Resolution of the picture check (default 72)
  --password <text>            Password of an encrypted input
Common: -o --force --dry-run --json -j   (deft help common)

Examples:
  deft pdf compare report.pdf appendix.pdf --json

Result fields: identical, pages, changes
  5. deft pdf compare paper.pdf paper-stamped.pdf --json
    output
    {"v":1,"ok":true,"op":"pdf.compare","items":[{"ok":true,"inputs":["paper.pdf","paper-stamped.pdf"],"outputs":[],"facts":{"identical":false,"pages":[14,14],"changes":[{"page":3,"added":["DRAFT"],"removed":[],"pixels":0.046180761867036374}]},"warnings":[]}],"elapsed_ms":315}
  6. printf '3\\n' > pages.txt
  7. Page 3 differs. I wrote `3` to [pages.txt](pages.txt).
Output
pages.txt 2 B
3

Claude Opus 5.5Without deftPassed2026-11-07


Time
23s
New tokens
11.3k
Total input
73.8k


Output tokens
1.5k
Commands
0
Failed
0


Trace
    Output
    pages.txt 2 B
    3

    Claude Opus 5.5With deft, skill installedPassedRead the skillUsed deft2026-11-07
    

    Time
    13s
    New tokens
    10.3k
    Total input
    75.1k
    

    Output tokens
    0.6k
    Commands
    0
    Failed
    0
    

    Trace
      Output
      .claude/skills/deft/SKILL.md 2.1 KB
      ---
name: deft
description: "Use deft first for any simple, direct operation on local files, whatever the type: convert, read, extract, edit, compress, merge, split, compare or inspect. Try it before writing a script or one-liner. If unsure, run deft find; if it says no command does this, use another tool. Not for programming work: to read, write or change source code, skip it."
---

# deft

One local command for file jobs. Prefer it over writing Python or shell scripts.

Syntax: `deft <group> <command> [inputs] [-o output] [--options]`

Groups:
- `pdf`: Merge, split, compress, encrypt, forms, OCR, compare, convert
- `image`: Resize, crop, convert, compress, adjust, montage, OCR
- `video`: Trim, merge, convert, compress, subtitles, GIF, frames (ffmpeg)
- `audio`: Convert, trim, normalize, denoise, cut silence (ffmpeg)
- `doc`: Word/ODT/RTF: to text, Markdown, HTML, PDF; find and replace
- `slides`: PowerPoint: extract text, Markdown outline
- `sheet`: Excel/CSV/ODS tables: SQL query, pivot, merge, split, convert
- `json`: JSON: convert, format, merge, diff, validate
- `toml`: TOML: convert, format, merge, diff, validate
- `xml`: XML: convert, format, merge, diff, validate
- `yaml`: YAML: convert, format, merge, diff, validate
- `md`: Markdown to PDF, HTML, Word, EPUB; table of contents
- `html`: HTML to Markdown, text, Word and PDF
- `epub`: E-books: info, to text, Markdown and PDF
- `gps`: GPX and KML tracks: convert, distance and time
- `qr`: Create QR codes and barcodes; read QR codes

How to use it:
1. Run `deft <group>` to list commands, or `deft find "<what you want>"` to search. If it says `no command does this`, use another tool.
2. Run `deft <group> <command> --help` for options and examples.
3. `deft convert <in> -o <out.ext>` converts between formats by extension.
4. Results are one line starting with `ok`, `partial` or `error`; add `--json` to parse them. Errors include a `hint:` with the fix.

Inputs are never overwritten; pass `--force` or `--in-place` to allow it. Globs and directories work as inputs; several inputs run in parallel.

If `deft` is not installed, ask the user, then follow https://github.com/firstprayer/deft/blob/main/docs/INSTALL.md

      pages.txt 2 B
      3

      Claude CodeWithout deftNot run yet
      Claude CodeWith deftNot run yet