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sdffy diffs people can read

sdffy compares two versions of a config, a spec or a contract and tells you what actually changed — in plain words, grouped by meaning, not by line numbers.

YAML · JSONconfigs
Markdown · DOCXdocuments
Local-firstyour files stay yours

A line-by-line diff tells you which characters moved. sdffy tells you what that means: a value changed, a section was removed, a list was only reordered. Reviewers who don't read YAML all day can finally sign off on a change with confidence.

Why sdffy

Classic diffs were built for code. Most of what teams review isn't code.

Plain diff

Forty red and green lines

Indentation shifts, reordered keys and moved paragraphs all look like real changes. The one line that matters hides in the noise.

sdffy

Four sentences

Changes are matched by structure and meaning. Pure moves and formatting are folded away, and every real change is described in a short sentence.

  • Ignores formatting-only noise: whitespace, key order, line wrapping.
  • Groups related edits, so “renamed a service everywhere” is one item, not twenty.
  • Shareable summaries for people who approve changes but don't read raw files.

How it works

Three steps, all on your machine.

ParseBoth versions are read as structure — trees for configs, sections and paragraphs for documents.
MatchNodes are paired by key, position and content, so moves and renames are recognised.
DescribeEach real difference becomes one readable line you can copy, comment on or export.
# compare two files
sdffy old.yaml new.yaml

# compare a file with its previous git revision
sdffy config/app.json@HEAD~1 config/app.json

What it reads

Structured formats first; more on the way.

configs

YAML, JSON, TOML, INI and .env files.

Compared as trees, not as text.

documents

Markdown and DOCX.

Compared by section and paragraph.

tables

CSV and TSV.

Rows matched by key column, not by position.

Privacy

Your files never leave your device.

Local-first
All parsing and comparison happens on your computer or phone. sdffy has no account system and does not upload documents anywhere.

Status

sdffy is in private beta.

  1. 1NowPrivate beta of the desktop app and command-line tool.
  2. 2NextPublic desktop release for macOS, Windows and Linux.
  3. 3LaterMobile apps for reviewing summaries on the go.

The site is being rebuilt; documentation and downloads will appear here when the public release is ready.