Flatten JSON Object

Nested JSON is elegant for humans and a problem for every flat consumer downstream: environment variables, feature-flag systems, simple key-value stores and spreadsheet exports all want one level. When the configuration lives four levels deep, someone has to walk it and hand-write the flattened form — a slow, error-prone mapping that must be redone every time the structure changes.

Flatten JSON Object turns any nested object into a single level with zero effort. Every path becomes one key — settings.limits.max_items with a dot separator, settings_limits_max_items with an underscore — so the key itself carries the full history of where the value lived. Arrays flatten with indices or collapse to JSON strings, whichever your consumer prefers. Omit nulls and empties for clean config, or include them for complete data coverage, sort alphabetically or keep encounter order, and verify the result in a two-column table preview. All client-side, nothing uploaded.

• Dot or underscore separators: Choose the key style your consumer expects — dotted paths or env-var-style underscores.
• Two array strategies: Flatten arrays with indices (items.0.name) or keep them as JSON-string values.
• Empty-value control: Omit nulls, empty objects and empty arrays, or include every branch explicitly.
• Sort keys alphabetically: For diff-friendly, deterministic output, or keep document encounter order.
• Table preview: Verify the result as a path/value table before shipping it.
• Pretty or compact output: Match the style to the consumer.
• Live conversion: The flat object updates as you type or change options.
• Copy and download: Export the flat object or the table in one click.
• Private: Everything runs in your browser; nothing is uploaded.

1. Paste your nested JSON object into the input pane.
2. Choose the separator — dot for readable paths, underscore for env-var style keys.
3. Pick the array strategy — indexed paths for data, JSON strings for config.
4. Set empty-value and sorting options to match your consumer.
5. Verify in the table preview, then copy or download the flat object.

Example 1 — Config to environment variables. A twelve-factor app needs every config value as an env var. The nested config flattens with underscore separators into APP_SETTINGS_LIMITS_MAX_ITEMS=50 — names the deployment team can read at a glance and wire into the platform in minutes.

Example 2 — Feature flags. A flag service accepts flat JSON. The nested flags object flattens with dot separators: notifications.email.enabled, notifications.push.enabled — each flag becomes one key the service can evaluate without a path walker.

Example 3 — Comparing configs across environments. Dev, staging and prod configs flatten, sort, and diff in one pass. The dotted keys make the differences read as exact locations: staging.retries=1 vs prod.retries=3.

Example 4 — Database column mapping. An export job needs one column per field. Indexed array mode yields order.items.0.sku as a real column key, and include-empty guarantees the schema is complete even when values are absent.

• Every consumer gets a flat structure: Env vars, flag services, spreadsheets and KV stores accept the output directly.
• Self-describing keys: Each key encodes its full path — no lookup table needed.
• Diff-friendly and deterministic: Sorted flat output compares cleanly between environments and versions.
• No hand-written mappings: The flattening updates itself whenever the source structure changes.
• Safe and instant: Client-side processing with a live preview and zero uploads.