Add your JSON file
Drop one or more .json files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
JSON to BSON
Restructuring .json data as .bson changes the serialization without touching the values themselves. Free, private, and validated — the file never leaves your browser.
Private for supported formats — processed in your browser
Runs on your deviceConvert supported files
Drop JSON files here
Batch files can each use a different output. Nothing uploads for local conversions.
Working inputs include camera RAW, browser-local audio/video, PDF, CBZ/CBR comics, office documents, ebooks, markup, 3D models, structured text, images, and archives.About converting JSON data to BSON
Restructuring .json data as .bson changes the serialization without touching the values themselves. A .json file holds JavaScript Object Notation: nested objects, arrays, strings, numbers, booleans, and null written in a strict text syntax. It is the default data language of the web — most APIs speak nothing else.
A .bson file holds BSON: the binary document format MongoDB stores and transmits. It looks like JSON with types added — every field is length-prefixed and carries a type byte — which makes documents skippable during a scan and gives them an ObjectId, a real date type, and 32- and 64-bit integers distinct from doubles. For this route the practical draw is exact numeric types and native dates, unlike JSON and length prefixes make skipping and partial reads cheap — balanced against often larger than the equivalent JSON, because of length prefixes and field names repeated per document, which is worth knowing before you commit a large batch.
Why convert JSON to BSON?
The practical trigger for this conversion is usually a mismatch: with .json, no comments — a perpetual annoyance for configuration files. Switching to .bson buys you exact numeric types and native dates, unlike JSON, which is why it is the better fit for inspecting a mongodump export without restoring it to a database. Because the conversion runs locally, trying it costs nothing but a few seconds of compute on your own machine.
JSON vs BSON at a glance
| Aspect | JSON data (.json) | BSON (.bson) |
|---|---|---|
| Format type | Text-based — characters and structure, so there is no visual quality loss | Lossless — every pixel or sample is preserved exactly |
| How it stores data | exactly six value types; no dates, no comments, no trailing commas — the strictness is deliberate | a document is a little-endian int32 total length, a sequence of typed elements, and a terminating null byte |
| Strongest at | rEST and HTTP API request and response payloads | inspecting a mongodump export without restoring it to a database |
| Weak spot | no comments — a perpetual annoyance for configuration files | often larger than the equivalent JSON, because of length prefixes and field names repeated per document |
Pick BSON as the output
Select .bson in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if BSON is selectable, the route is real and validated.
Convert on your device
Press Convert. The restructuring is plain local parsing — your data is never posted to a server for processing.
Verify and download
Each result is signature-checked before the download unlocks, so a failed encode can never masquerade as a valid BSON file. Outputs keep the original filename with the .bson extension.
JSON to BSON questions, answered
Will converting JSON to BSON lose quality?
There is no visual quality to lose — json is text-oriented and bson is lossless-oriented, so the question is structural fidelity. Text, ordering, and basic structure are preserved; complex layout, embedded objects, and styling beyond the target's model are simplified.
Is it private to convert JSON files here?
Yes — the .json file is processed inside your browser tab and never uploaded. The restructuring is plain local parsing — your data is never posted to a server for processing. Close the tab and the file is gone from memory.
Where will the BSON file work?
Official MongoDB drivers for every major language decode BSON, and standalone libraries exist for Python, Java, Go, Rust and JavaScript. Novus Convert decodes .bson in the browser and writes JSON, CSV, XLSX, YAML or YML, handling non-JSON types explicitly: ObjectId and Decimal128 become their canonical string forms and Binary is reported rather than mangled into text.
Will the BSON file be bigger or smaller than my JSON?
It depends on the content: a document is a little-endian int32 total length, a sequence of typed elements, and a terminating null byte. Convert one representative file first and compare before batch-processing a large set.
Can I convert BSON back to JSON?
Yes — the reverse route exists as a separate tool. Bear in mind that round-tripping .json → .bson → .json is not a perfect undo when any lossy step is involved; keep your original if fidelity matters.