promptdiff

Compare prompt versions. See what broke your AI.

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Install

npm install -g promptdiff

Usage

# compare two prompt files
promptdiff v1.txt v2.txt

# inline diff (shows changes within text)
promptdiff v1.txt v2.txt --format inline

# side by side view
promptdiff v1.txt v2.txt --format side

# compare text directly
promptdiff -t "You are a helpful assistant" "You are a coding expert"

# stats only
promptdiff v1.txt v2.txt --stats
# prompt diff stats:
#   before:     15 words, 89 chars
#   after:      18 words, 102 chars
#   added:      5
#   removed:    2
#   unchanged:  13
#   similarity: 72%

Output Formats

Unified (default)

--- prompt-v1.txt
+++ prompt-v2.txt

  You are a
- helpful assistant.
+ coding expert.
  Be concise
+ and precise.

// 72% similar | +5 -2

Inline

You are a [-helpful assistant.][+coding expert.] Be concise[+ and precise.]

Side by Side

┌──────────────────────┬──────────────────────┐
│ BEFORE               │ AFTER                │
├──────────────────────┼──────────────────────┤
│ You are a helpful    │ You are a coding     │
│ assistant.           │ expert.              │
│ Be concise.          │ Be concise and       │
│                      │ precise.             │
└──────────────────────┴──────────────────────┘

Options

| Flag | Description | Default | |------|-------------|---------| | -f, --format | Output format: inline, unified, side | unified | | -t, --text | Compare text strings directly | false | | -s, --stats | Show statistics only | false | | --no-color | Disable colored output | false | | -w, --width | Width for side-by-side view | 40 | | -o, --output | Save diff to file | - |

Pro Tips

Version control your prompts

# see what changed since last commit
promptdiff <(git show HEAD~1:prompt.txt) prompt.txt

# compare branches
promptdiff <(git show main:prompt.txt) <(git show feature:prompt.txt)

Track prompt evolution

# save diffs for documentation
promptdiff v1.txt v2.txt -o changelog/v1-v2.diff

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License

MIT © pnkd.dev

pnkd.dev — glitch the system. break the prompt.