Evals / pdf / Compress

Compress a photo-heavy PDF

Reduce photos.pdf to less than half its size and save it as light.pdf.

normalsingledeft pdf compress

The task

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

deft pdf compress photos.pdf --level strong -o light.pdf

Input

photos.pdf 703.6 KB · 1 page
Page 1

Reference output

light.pdf 68.0 KB · 1 page
Page 1
How a result is judged (3 checks)
  • pdf_pages: file = "light.pdf", pages = 1
  • max_bytes: file = "light.pdf", bytes = 360000
  • pdf_page: file = "light.pdf", page = 1, ink_min = 0.2

Runs

CodexWithout deftPassed2026-11-07

Time
10s
New tokens
3.4k
Total input
40.2k
Output tokens
0.3k
Commands
2
Failed
0

Trace

  1. I’ll inspect the PDF’s size and available local PDF tools, then create `light.pdf` here and check the resulting file size.

  2. pwd && ls -lh photos.pdf && command -v gs || true && command -v qpdf || true && command -v mutool || true && command -v pdfimages || true
    output
    -rw-r--r--@ 1 user  staff   704K Nov  5 21:11 photos.pdf
/usr/local/bin/gs
  3. gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/screen -dNOPAUSE -dQUIET -dBATCH -sOutputFile=light.pdf photos.pdf && ls -lh photos.pdf light.pdf
    output
    -rw-r--r--@ 1 user  staff    36K Nov  6 17:16 light.pdf
-rw-r--r--@ 1 user  staff   704K Nov  5 21:11 photos.pdf

  4. Created [light.pdf](light.pdf). It’s 36 KB, down from 704 KB—about 5% of the original size.

Output

light.pdf 35.8 KB · 1 page
Page 1

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

Time
12s
New tokens
4.5k
Total input
56.5k
Output tokens
0.3k
Commands
3
Failed
0

Trace

  1. I’ll check the PDF’s size and use the available file-processing workflow to compress it, then confirm the output is under half the original size.

  2. cat .agents/skills/deft/SKILL.md && pwd && ls -lh photos.pdf
    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
… 786 more characters
  3. deft pdf compress --help
    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
  4. deft pdf compress photos.pdf --target-size 350000 -o light.pdf
    output
    ok pdf.compress photos.pdf -> light.pdf  704KB -> 272KB (-61%)  0.06s

  5. Compressed [light.pdf](light.pdf) to 272 KB, down from 704 KB—about 39% of the original size.

Output

light.pdf 272.3 KB · 1 page
Page 1

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

Time
13s
New tokens
9.5k
Total input
60.4k
Output tokens
0.4k
Commands
3
Failed
0

Trace

  1. I’ll check the PDF’s size and available `deft` compression options, then save the compressed copy as `light.pdf` in this directory.

  2. deft pdf --help && ls -lh photos.pdf
    output
    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
-rw-r--r--@ 1 user  staff   704K Nov  4 19:32 photos.pdf

  3. `photos.pdf` is 704 KB, so the target is below 352 KB. I’m using `deft`’s strongest compression setting and will check the result size.

  4. deft pdf compress --help
    output
    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
  5. deft pdf compress photos.pdf --level strong --target-size 351000 -o light.pdf && ls -lh light.pdf
    output
    ok pdf.compress photos.pdf -> light.pdf  704KB -> 272KB (-61%)  0.06s
-rw-r--r--@ 1 user  staff   272K Nov  4 19:57 light.pdf

  6. Done. [light.pdf](light.pdf) is 272 KB, down from 704 KB (61% smaller).

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
21s
New tokens
11.9k
Total input
104.8k
Output tokens
1.6k
Commands
0
Failed
0

Trace

    Output

    light.pdf 45.2 KB · 1 page
    Page 1

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

    Time
    16s
    New tokens
    10.5k
    Total input
    75.7k
    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
      light.pdf 272.3 KB · 1 page
      Page 1

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