Selected BSON and Extended JSON Inspector

How to use Selected BSON and Extended JSON Inspector

Inspect one BSON byte document with ordered typed fields and export selected Canonical Extended JSON without rounding int64 values. Use raw file, hexadecimal or Base64 input to examine document boundaries, source offsets and binary types. Duplicate and dollar-prefixed fields retain witnesses and suppress ambiguous EJSON conversion.

1. Provide optional single bson document, bson hexadecimal or padded base64.
2. Choose the supported mode and run the tool. Review its assumptions and any reported errors.
3. Copy the result or download a separate output; reset to clear the current form.

Good to know

• Selected BSON 1.1 profile: document, array, double, UTF-8 string, opaque binary, ObjectId, boolean, UTC datetime, null, regex data, int32, internal timestamp, int64, MinKey and MaxKey. Decimal128, deprecated Undefined/DBPointer/Code/Symbol/CodeWithScope and unknown element types are refused up front. No full MongoDB-driver conformance is claimed.
• Exactly one document of 5–65,536 bytes, at most 12 document/array levels and 1,000 total elements. Names/regex cstrings are limited to 1,024 UTF-8 bytes; string payloads to 32,768. Declared lengths, containing boundaries, NUL terminators, boolean bytes and consecutive array indexes are checked before reading values. Pasted input is capped at 200 KB.
• Signed 64-bit integer and date millisecond values remain decimal strings. Timestamps retain separate unsigned 32-bit time/increment components. Doubles keep their eight source bytes; EJSON normalizes NaN payloads and numeric spelling. No calendar-range, ObjectId identity, date validity or MongoDB query/storage policy is inferred.
• Binary subtypes are retained as numeric hex identifiers plus exact payload Base64, including legacy subtype 2 inner-length checks. They are not UUID byte-order conversions, encrypted-value verification, vector parsing or compressed-column expansion. Reserved subtype semantics are unassessed. Regex pattern/options are data and are never compiled or executed.
• Ordered typed field entries preserve duplicates and prototype-like names safely. Any duplicate field or any dollar-prefixed document field suppresses EJSON export, because a JSON object or type wrapper could change its meaning. Array indexes remain ordered. JSON objects do not guarantee BSON field order and exported EJSON is not a byte-preserving BSON backup.
• The separate download is Canonical EJSON only when conversion is unambiguous; otherwise it is the structured inspection report. EJSON is capped at 250,000 characters and the full report at 500,000. Processing uses a dedicated Worker with 10-second preparation and a separate 2-second computation deadline. No database, network, user code, decompression or files beyond the selected input are accessed.
• The formatted report is limited to 500,000 characters. Reduce the source when that output budget is exceeded.
• Inputs are processed on this device and are not automatically saved or uploaded.