LogShaper

JSON to JSON Schema generator

Q: Can I see the data as a table too?

Yes. The Formatted JSON and Data Grid tabs show the same records, and each tab has a download button.

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Sanitization Rules

Mask IPs Scrub keys/tokens Redact emails

Quick samples:

Raw unstructured logs

Ctrl/⌘ + Enter to parse

No data processed yet.

/* Click "Parse & Normalize Schema" to process raw logs */

/* Generated JSON Schema will appear here */

JSON to JSON Schema, right in your browser

Paste a JSON object, an array of objects, or newline-delimited JSON (JSON Lines) and LogShaper infers a JSON Schema from it. The more samples you give it, the better it gets: a field that's missing from some records is left out of required, and a field that's sometimes null becomes nullable.

How to use it

Paste your logs into the box above. An example is already loaded so you can see the result.
Choose what to redact: IP addresses, keys and tokens, and emails are all on by default.
Click Parse & Normalize Schema, then copy or download the JSON, the JSON Schema, or a CSV from the Data Grid.

What you get

Types: string, integer vs number, boolean, null, object and array
Mixed types: a field seen as both a number and null becomes ["number", "null"]
required: keys present in every sample
Nested objects and arrays: described recursively, including array item types
Formats: ISO 8601 timestamps get "format": "date-time"
Enums: a level field gets an enum of the values seen

Example

Input

[
  {
    "id": 1001,
    "name": "Ada Lovelace",
    "email": "[email protected]",
    "signup": "2026-11-01T14:03:00Z",
    "plan": "pro",
    "tags": ["beta", "early"],
    "address": { "city": "London", "zip": null }
  },
  {
    "id": 1002,
    "name": "Alan Turing",
    "email": "[email protected]",
    "signup": "2026-11-03T09:15:00Z",
    "plan": "free",
    "tags": [],
    "score": 98.5
  }
]

Output (JSON Schema)

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "LogShaperInferredSchema",
  "description": "Inferred from 2 log entries",
  "type": "object",
  "properties": {
    "id": {
      "type": "integer"
    },
    "name": {
      "type": "string"
    },
    "email": {
      "type": "string"
    },
    "signup": {
      "type": "string",
      "format": "date-time"
    },
    "plan": {
      "type": "string"
    },
    "tags": {
      "type": "array",
      "items": {
        "type": "string"
      }
    },
    "address": {
      "type": "object",
      "properties": {
        "city": {
          "type": "string"
        },
        "zip": {
          "type": "null"
        }
      },
      "required": [
        "city",
        "zip"
      ]
    },
    "score": {
      "type": "number"
    }
  },
  "required": [
    "id",
    "name",
    "email",
    "signup",
    "plan",
    "tags"
  ]
}

Questions

Which JSON Schema version is generated?

Draft 2020-12, the current version, which recent validators such as Ajv support.

Can I paste pretty-printed JSON?

Yes. A single object or an array of objects spread over many lines works, and so does JSON Lines with one object per line.

Can I see the data as a table too?

Yes. The Formatted JSON and Data Grid tabs show the same records, and each tab has a download button.

Is my data uploaded anywhere?

No. Parsing, redaction and schema generation all run in your browser tab. The page's security policy blocks every network request, so pasted logs can't be sent anywhere, and nothing is saved when you close the tab.

More LogShaper tools

Nginx log to JSONAccess logs to structured JSON fields Redact secrets from logsScrub API keys, tokens, emails and IPs Parse stack tracesJava, Python and Node.js traces to JSON Syslog to JSONLinux system logs to structured records logfmt to JSONkey=value logs to typed JSON

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LogShaper has no ads, no tracking and no sign-up, and that's not going to change. If it saved you some time, a small donation helps cover hosting and new features.

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