NDJSON → VTT
Convert NDJSON files to VTT entirely in your browser — no upload, no watermark, no sign-up.
Drop files here
or browse from your device
images · audio · video · documents · archives · up to ~500MB
Your first conversion lands here automatically — saved on this device only, never uploaded.
100% Private
Runs in your browser. No upload.
Instant
No queue, no server roundtrip.
Offline-ready
Works after first load.
Converting NDJSON data to VTT is a shape change — the same records expressed the way the next tool in your pipeline expects to read them. VTT (WebVTT subtitle) earns its place here: native browser captions with styling and positioning control. NDJSON is the same one-object-per-line convention as JSON Lines, used by log shippers, APIs and bulk-import endpoints.
NDJSON is the same one-object-per-line convention as JSON Lines, used by log shippers, APIs and bulk-import endpoints.
Records and field names carry over from NDJSON to VTT one-for-one. The real difference is shape: nested structures flatten when the target is tabular, and flat rows gain a wrapper when the target is hierarchical. Types are preserved where VTT has a way to express them, otherwise values become plain strings.
What you gain with VTT: Native browser captions with styling and positioning control.
Drop your NDJSON file above and Morphio decodes it locally, then re-encodes it as VTT using WebAssembly + the browser's native codecs. Nothing is ever uploaded — your files stay on your device. Batch as many files as your machine can handle. See exactly how in-browser conversion works.
Open the NDJSON to VTT page, drop your document on the drop zone and press convert. Morphio runs local parsers such as pdf.js that execute in your own tab, so the NDJSON data never leaves your device and no server ever receives a copy.
Text and structure are read locally, so nothing is retyped, re-uploaded, or sent to an OCR service. Converting NDJSON to VTT only rewrites the container and encoding you asked for — the source file on your disk is never modified.
Yes. The free plan covers 10 conversions a day with files up to 200 MB and adds no watermark or sign-up. Morphio Pro ($5/month, or $29 once for lifetime access) removes the daily cap and raises the per-file limit to 5 GB.
No. The content is remapped from NDJSON into VTT structurally, so nothing is re-compressed. Only features VTT has no way to express are left behind.
Yes — drop the whole batch in and each file is processed in turn on your own machine. The practical limit is your device's memory and patience, not a server quota, because nothing is queued anywhere else.
No. The conversion runs entirely inside your browser using WebAssembly, so the file never leaves your device — you can disconnect from the internet after the page loads and it still works.