jsonyo

JSON swiss army knife. Eighteen commands. Zero limits. Free forever. A gift to the terminal from vøiddo.

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Why jsonyo

Every other JSON CLI gives you three commands and paywalls the rest. jq is powerful but hostile. Online editors leak your data. Online formatters die on anything over a megabyte.

jsonyo is one binary, eighteen commands, and no artificial limits. No file-size caps. No daily quota. No PRO tier. No sign-up. No telemetry. No "upgrade to unlock" nag screens. You install it, you use it, it works.

It exists because we got tired of paying $9.99/mo to format JSON that already lived on our own laptop.

Install

# npm
npm install -g @v0idd0/jsonyo

# or pnpm / yarn / bun
pnpm add -g @v0idd0/jsonyo
yarn global add @v0idd0/jsonyo
bun add -g @v0idd0/jsonyo

# one-shot via npx (no install)
npx @v0idd0/jsonyo format data.json

Requires Node.js ≥ 14.

The Commands

| Command | What it does | |---|---| | validate · v | Check if JSON is valid (optionally against a JSON Schema) | | format · f | Pretty-print with custom indent, tabs, sorted keys, fixed key order, trailing commas | | minify · m | Compress to a single line | | query · q | Extract values by JSONPath (filters, recursion, wildcards) | | keys · k | List every key at any depth | | type · t | Show inferred type and structural summary | | diff · d | Compare two files — text diff or RFC 6902 patch | | stats · s | Cardinality + shape statistics | | merge | Merge unlimited files (last-wins, deep, or custom conflict strategy) | | flatten | Flatten nested JSON with a custom separator | | unflatten | Reverse it — rebuild nesting from dotted keys | | sort | Sort keys or arrays by one or many fields | | filter | Filter array elements with expressive predicates | | convert | JSON ↔ YAML, TOML, CSV, XML — both directions | | schema | Generate a JSON Schema from data, or validate against one | | generate | Generate TypeScript, Go, Python, or Rust types from a sample | | batch | Process thousands of files at once with glob patterns | | watch | Watch files and auto-process on change |

Usage

# validate
jsonyo validate data.json
cat data.json | jsonyo v

# format (4 spaces, keys sorted)
jsonyo format data.json -i 4 --sort-keys

# minify + save
jsonyo minify huge.json -o huge.min.json

# JSONPath query
jsonyo query users.json -p "$.users[?(@.age > 18)].email"

# diff as patch
jsonyo diff old.json new.json --format patch

# merge — unlimited files, deep strategy
jsonyo merge a.json b.json c.json d.json --strategy deep -o combined.json

# flatten with custom separator
jsonyo flatten nested.json --separator /

# sort by multiple keys
jsonyo sort data.json --by "country,name"

# filter with a predicate
jsonyo filter users.json --where "age > 18 && active"

# convert to YAML / TOML / CSV / XML
jsonyo convert data.json --to yaml
jsonyo convert data.json --to csv -o data.csv

# generate TypeScript types
jsonyo generate types response.json -o types.ts

# batch — glob across thousands of files
jsonyo batch format "./data/**/*.json" --sort-keys

# watch — auto-validate on save
jsonyo watch validate "./src/**/*.json"

Pipe-friendly

Every command reads from stdin when no file is given, so jsonyo plays well with the rest of your toolbox.

curl -s https://api.example.com/data | jsonyo format -i 2
kubectl get pods -o json | jsonyo query -p "$.items[*].metadata.name"
aws ec2 describe-instances | jsonyo filter --where "State.Name == 'running'"

Big files, big pipelines

• No 10 MB cap — if your laptop can hold it, jsonyo can chew it.
• No op-per-day limit — loop it, cron it, bake it into CI.
• No network calls — jsonyo is a local CLI. Your JSON never leaves your machine.

Why free forever

We are vøiddo — a studio building small, sharp tools and a few serious products (scrb, rankd, gridlock, and more). The serious products pay for themselves. The tools are gifts.

We write them because we need them, and leaving them free means we don't have to build a billing flow for a terminal utility.

From the same studio

• @v0idd0/tokcount — count LLM tokens before you pay for them
• @v0idd0/envguard — stop shipping .env drift to staging
• @v0idd0/depcheck — find unused dependencies
• @v0idd0/gitstats — git repo analytics, one command
• View all tools →

Contributing

Bugs, feature ideas, PRs welcome. Open an issue at github.com/voidd0/jsonyo/issues or drop a line to [email protected].

License

MIT — see LICENSE.

Built by vøiddo — a small studio shipping AI-flavoured products, free dev tools, Chrome extensions and weird browser games.