Evals / pdf / Compress

Shrink a scan for email

scan.pdf is too big to email. Make a copy called small.pdf under 150KB that is still readable.

normalsinglesmokedeft pdf compress

The task

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

deft pdf compress scan.pdf --target-size 150KB -o small.pdf

Input

scan.pdf 244.8 KB · 4 pages
Page 1Page 2Page 3

Reference output

small.pdf 112.9 KB · 4 pages
Page 1Page 2Page 3
How a result is judged (3 checks)
  • pdf_pages: file = "small.pdf", pages = 4
  • max_bytes: file = "small.pdf", bytes = 153600
  • pdf_page: file = "small.pdf", page = 1, ink_min = 0.02

Runs

CodexWithout deftFailed2026-11-07

small.pdf is 198697 bytes, limit 153600

Time
56s
New tokens
12.7k
Total input
179.1k
Output tokens
2.2k
Commands
11
Failed
3

Trace

  1. I’ll inspect the PDF and available local compression tools, then create `small.pdf` in this directory and check its size and legibility.

  2. ls -lh scan.pdf && file scan.pdf && command -v gs && command -v qpdf && command -v pdftoppm && command -v pdfinfo (exit 1)
    output
    -rw-r--r--@ 1 user  staff   245K Nov  5 21:11 scan.pdf
scan.pdf: PDF document, version 1.3, 4 pages
/usr/local/bin/gs
  3. command -v pdfinfo; command -v pdftoppm; command -v identify; command -v magick; gs -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/ebook -dDetectDuplicateImages=true -dCompressFonts=true -sOutputFile=small.pdf scan.pdf && ls -lh small.pdf && file small.pdf
    output
    -rw-r--r--@ 1 user  staff   270K Nov  6 17:17 small.pdf
small.pdf: PDF document, version 1.4, 4 pages
  4. gs -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/screen -dDetectDuplicateImages=true -dCompressFonts=true -sOutputFile=<tmp> scan.pdf && ls -lh <tmp> && pdfinfo scan.pdf && pdfinfo <tmp> (exit 127)
    output
    -rw-r--r--@ 1 user  wheel   737K Nov  6 17:17 <tmp>
zsh:1: command not found: pdfinfo
  5. which mutool; which pdftocairo; which python3; python3 -c 'import importlib.util as u; print({m:bool(u.find_spec(m)) for m in [\"pypdf\",\"fitz\",\"PIL\",\"pdf2image\"]})'; gs -q -dNOPAUSE -dBATCH -sDEVICE=inkcov scan.pdf (exit 1)
    output
    mutool not found
pdftocairo not found
/usr/local/bin/python3
{'pypdf': False, 'fitz': False, 'PIL': True, 'pdf2image': False}
GPL Ghostscript 9.55.0: Device 'inkcov' requires an output file but no file was specified.
Error: /undefinedfilename in --showpage--
Operand stack:
   1   true
Execution stack:
   %interp_exit   .runexec2   --nostringval--   showpage   --nostringval--   2   %stopped_push   --nostringval--   showpage   showpage   false   1   %stopped_push   1974   1   3   %oparray_pop   1973   1   3   %oparray_pop   1961   1   3   %oparray_pop   1962   1   3   %oparray_pop   showpage   showpage   2   1   4   showpage   %for_pos_int_continue   1965   1   7   %oparray_pop   showpage   showpage   1824   0   9   %oparray_pop   showpage   showpage
Dictionary stack:
   --dict:758/1123(ro)(G)--   --dict:1/20(G)--   --dict:81/200(L)--   --dict:81/200(L)--   --dict:134/256(ro)(G)--   --dict:324/325(ro)(G)--   --dict:33/64(L)--   --dict:6/9(L)--   --dict:6/20(L)--
Current allocation mode is local
Last OS error: No such file or directory
GPL Ghostscript 9.55.0: Unrecoverable error, exit code 1

  6. The standard Ghostscript presets expanded this file, so I’m tuning image downsampling and JPEG quality directly to get below the limit without rasterizing text that may already be vector based.

  7. gs -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dColorImageDownsampleType=/Bicubic -dColorImageResolution=100 -dGrayImageDownsampleType=/Bicubic -dGrayImageResolution=100 -dMonoImageDownsampleType=/Subsample -dMonoImageResolution=150 -dJPEGQ=55 -dDetectDuplicateImages=true -dCompressFonts=true -sOutputFile=<tmp> scan.pdf && ls -lh <tmp>
    output
    -rw-r--r--@ 1 user  wheel   270K Nov  6 17:17 <tmp>
  8. strings scan.pdf | head -80
    output
    %PDF-1.3
%%Invocation: gs -q -dNOPAUSE -dBATCH -sDEVICE=pdfimage24 -r110 -dLastPage=4 -sOutputFile=? ?
4 0 obj
/Length 5 0 R
/Subtype /Image
/Width 935
/Height 1210
/ColorSpace /DeviceRGB
/BitsPerComponent 8
/Filter /FlateDecode
stream
MkG|
m@xM
pO>_}
{Bs.
^\qv
]K{!
3+'U
Sur8
tf9%3
+J^N
kIN-
_N2N
o&yJg
99L%
3rzW
j;8M
=~GO-
NNuF
fX=l
rpTmY+
x&6
}Y?p
.udc
yp*l[
UbiXQ
)UJ~
p)g?
j6[?
YNL`jL:
8"I=@
G}\4M
U{<.
J?Wc
H =/
0rH`Od
_w/]==
,av,M
jr|]:/P
WW]:
ZHxM
;vmT
5;6{
k^*U
0]]G
X5w*
b@\+M
0-Jw
g:@/
W-zi2Wlz
b|,y
>n&l
]wH@
`=~aX57
vX{"
b-1}
HR'_
Wgs*
E:s?
K?p^
_*}2
[D3oF
tS;^
3rV&
)lzoX+
)Vt =}N
UOU1u
qb;7]1.
&3g'
_0uv
  9. gs -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dAutoFilterColorImages=false -dColorImageFilter=/DCTEncode -dColorImageDownsampleType=/Bicubic -dColorImageResolution=110 -dJPEGQ=55 -dDetectDuplicateImages=true -sOutputFile=<tmp> scan.pdf && ls -lh <tmp>
    output
    -rw-r--r--@ 1 user  wheel   891K Nov  6 17:17 <tmp>
  10. gs -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -sColorConversionStrategy=Gray -dProcessColorModel=/DeviceGray -dAutoFilterColorImages=false -dColorImageFilter=/DCTEncode -dColorImageDownsampleType=/Bicubic -dColorImageResolution=110 -dJPEGQ=45 -dDetectDuplicateImages=true -sOutputFile=<tmp> scan.pdf && ls -lh <tmp>
    output
    -rw-r--r--@ 1 user  wheel   194K Nov  6 17:17 <tmp>
  11. gs -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -sColorConversionStrategy=Gray -dProcessColorModel=/DeviceGray -dAutoFilterColorImages=false -dColorImageFilter=/DCTEncode -dColorImageDownsampleType=/Bicubic -dColorImageResolution=80 -dJPEGQ=35 -dDetectDuplicateImages=true -sOutputFile=small.pdf scan.pdf && ls -lh small.pdf && file small.pdf
    output
    -rw-r--r--@ 1 user  staff   194K Nov  6 17:17 small.pdf
small.pdf: PDF document, version 1.4, 4 pages
  12. gs -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -sColorConversionStrategy=Gray -dProcessColorModel=/DeviceGray -dAutoFilterColorImages=false -dColorImageFilter=/DCTEncode -dColorImageDownsampleType=/Bicubic -dColorImageResolution=55 -dJPEGQ=25 -dDetectDuplicateImages=true -sOutputFile=<tmp> scan.pdf && ls -lh <tmp>
    output
    -rw-r--r--@ 1 user  wheel   194K Nov  6 17:17 <tmp>
  13. gs -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dDownsampleColorImages=true -dColorImageDownsampleType=/Bicubic -dColorImageResolution=40 -dDownsampleGrayImages=true -dGrayImageDownsampleType=/Bicubic -dGrayImageResolution=40 -dDownsampleMonoImages=true -dMonoImageResolution=80 -sColorConversionStrategy=Gray -dProcessColorModel=/DeviceGray -dAutoFilterColorImages=false -dColorImageFilter=/DCTEncode -dJPEGQ=20 -sOutputFile=<tmp> scan.pdf && ls -lh <tmp>
    output
    -rw-r--r--@ 1 user  wheel   207K Nov  6 17:17 <tmp>

  14. I couldn’t get `small.pdf` under 150 KB while keeping it readable. The smallest version I produced is 194 KB, so `small.pdf` is still over the limit.

Output

small.pdf 194.0 KB · 4 pages
Page 1Page 2Page 3

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

Time
14s
New tokens
8.2k
Total input
56.7k
Output tokens
0.4k
Commands
3
Failed
0

Trace

  1. I’ll inspect the PDF and use the available PDF compression workflow, then check the output size and readability.

  2. cat .agents/skills/deft/SKILL.md && rg --files -g 'scan.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
… 737 more characters

  3. The `deft` file workflow is available, so I’m checking its PDF compression options and the source PDF’s current size before choosing settings.

  4. deft pdf compress --help && ls -lh scan.pdf
    output
    deft pdf compress - Make smaller: --level, --target-size 2MB

Usage: deft pdf compress <pdf>... [-o <pdf|dir>] [options]
In: pdf (each handled separately)   Out: pdf (default <name>.compressed.<ext>)
Levels: lossless rewrites structure only; balanced re-encodes images
at JPEG 75, 150 dpi; strong at JPEG 55, 100 dpi.

Options:
  --level <lossless|balanced|strong>
      How hard to compress (default balanced)
  --target-size <bytes>        Try stronger settings until output <= this size
  --grayscale                  Convert images to grayscale
  --password <text>            Password of an encrypted input
Common: -o --force --dry-run --json -j   (deft help common)

Examples:
  deft pdf compress photos.pdf --level strong -o small.pdf
  deft pdf compress reports/*.pdf -o small/ --target-size 2MB

Result fields: bytes_before, bytes_after, ratio, images_recompressed
Errors: INPUT_ENCRYPTED, TARGET_UNREACHABLE
-rw-r--r--@ 1 user  staff   245K Nov  5 21:11 scan.pdf

  5. The source is 245 KB. I’ll use the target-size option to aim below 150 KB while preserving color unless the compressor needs stronger settings.

  6. deft pdf compress scan.pdf --target-size 150000 -o small.pdf
    output
    ok pdf.compress scan.pdf -> small.pdf  245KB -> 113KB (-54%)  0.06s

  7. Created [small.pdf](small.pdf) at 113 KB.

Output

small.pdf 112.9 KB · 4 pages
Page 1Page 2Page 3

CodexWith deft, skill as AGENTS.mdPassed2026-11-05

Time
13s
New tokens
6.1k
Total input
62.2k
Output tokens
0.4k
Commands
3
Failed
0

Trace

  1. I’ll inspect the PDF size and available `deft` compression options, then create and check `small.pdf` in this directory.

  2. pwd && ls -lh scan.pdf && deft pdf
    output
    -rw-r--r--@ 1 user  staff   245K Nov  4 19:32 scan.pdf
deft pdf - commands (input -> output)
  info         pdf -> report      Pages, size, metadata, fonts, images
  compress     pdf -> pdf         Make a PDF smaller: --level, --target-size 2MB
  delete       pdf -> pdf         Remove pages: --pages 2,5-7
  from-images  image... -> pdf    One page per image, in the given order
  from-md      md -> pdf          Typeset a PDF with headings, tables, code, images
  merge        pdf... -> pdf      Join PDFs in the given order
  number       pdf -> pdf         Add page numbers: --format "{n} of {total}"
  rotate       pdf -> pdf         Turn pages clockwise: --angle 90, --pages
  select       pdf -> pdf         Keep and reorder pages: --pages 3,1-2
  split        pdf -> pdf...      One file per page, or --every N, --ranges 1-3,4-
  to-images    pdf -> png|jpg...  Render pages to images: --dpi, --pages
  to-text      pdf -> txt         Extract text (form feed between pages)
  watermark    pdf -> pdf         Stamp text or an image on pages: --text, --image
More: deft pdf <command> --help
  3. deft pdf info scan.pdf && deft pdf compress --help
    output
    ok pdf.info scan.pdf  4 pages, letter, PDF 1.3
fonts=0 forms=false height=792.0 images=4 pages=4 paper=letter version=1.3 width=612.0
deft pdf compress - Make a PDF smaller: --level, --target-size 2MB

Usage: deft pdf compress <pdf>... [-o <pdf|dir>] [options]
In: pdf (each handled separately)   Out: pdf (default <name>.compressed.<ext>)
Levels: lossless rewrites structure only; balanced re-encodes images
at JPEG 75, 150 dpi; strong at JPEG 55, 100 dpi.

Options:
  --level <lossless|balanced|strong>
      How hard to compress (default balanced)
  --target-size <bytes>        Try stronger settings until output <= this size
  --grayscale                  Convert images to grayscale
  --password <text>            Password of an encrypted input
Common: -o --force --dry-run --json -j   (deft help common)

Examples:
  deft pdf compress photos.pdf --level strong -o small.pdf
  deft pdf compress reports/*.pdf -o small/ --target-size 2MB

Result fields: bytes_before, bytes_after, ratio, images_recompressed
Errors: INPUT_ENCRYPTED, TARGET_UNREACHABLE

  4. The source is a four-page image-only scan at 245 KB. I’m using the target-size compressor to meet the 150 KB limit and will verify the output file size.

  5. deft pdf compress scan.pdf --target-size 150000 -o small.pdf --force && ls -lh small.pdf
    output
    ok pdf.compress scan.pdf -> small.pdf  245KB -> 113KB (-54%)  0.07s
-rw-r--r--@ 1 user  staff   113K Nov  4 19:58 small.pdf

  6. Created [small.pdf](small.pdf) at 113 KB (under 150 KB). It remains a four-page scan, compressed with the target-size setting.

Output

Its files were not kept in this run. The last line of the trace is its own report.

Claude Opus 5.5Without deftPassed2026-11-07

Time
56s
New tokens
22.7k
Total input
201.5k
Output tokens
4.6k
Commands
0
Failed
0

Trace

    Output

    small.pdf 119.4 KB · 4 pages
    Page 1Page 2Page 3

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

    Time
    26s
    New tokens
    14.0k
    Total input
    147.4k
    Output tokens
    1.2k
    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
      small.pdf 112.9 KB · 4 pages
      Page 1Page 2Page 3

      Claude CodeWithout deftNot run yet

      Claude CodeWith deftNot run yet