Add your SUB file
Drop one or more .sub 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.
SUB to SAMI
Converting a .sub file to .sami extracts the document's content from its office package into a portable form. 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 SUB 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 MicroDVD subtitles to SAMI captions
Converting a .sub file to .sami extracts the document's content from its office package into a portable form. A .sub file in the MicroDVD convention is a frame-based subtitle list: every line reads {startFrame}{endFrame}text, with a pipe character separating the lines inside one cue. Because the timing is expressed in frames rather than milliseconds, a MicroDVD file only means anything alongside the frame rate of the video it was timed to.
A .sami file is the same Synchronized Accessible Media Interchange caption document as .smi, written with the long form of the extension. The contents are identical — <SYNC Start=…> elements inside an HTML-like SAMI document — and the long extension is chosen mainly to avoid colliding with SMIL files, which also claim .smi. For this route the practical draw is unambiguous about which format the file actually is and identical tooling support to .smi wherever SAMI is recognised — balanced against some players recognise only .smi and must be given a renamed copy, which is worth knowing before you commit a large batch.
Why convert SUB to SAMI?
The practical trigger for this conversion is usually a mismatch: with .sub, meaningless without the correct frame rate; the wrong value drifts the whole file. Switching to .sami buys you unambiguous about which format the file actually is, which is why it is the better fit for storing SAMI captions where .smi would collide with SMIL files. Because the conversion runs locally, trying it costs nothing but a few seconds of compute on your own machine.
SUB vs SAMI at a glance
| Aspect | MicroDVD subtitles (.sub) | SAMI captions (.sami) |
|---|---|---|
| Format type | Text-based — characters and structure, so there is no visual quality loss | Text-based — characters and structure, so there is no visual quality loss |
| How it stores data | each cue is one line: {startFrame}{endFrame} followed by the text, with | separating multiple display lines | byte for byte the same format as .smi: <SAMI>, <HEAD> with a <STYLE> block, and <BODY> with SYNC elements |
| Strongest at | playing back subtitles that were timed against a specific video rip | storing SAMI captions where .smi would collide with SMIL files |
| Weak spot | meaningless without the correct frame rate; the wrong value drifts the whole file | some players recognise only .smi and must be given a renamed copy |
| Metadata | there is no metadata section; the only header-like content is the frame-rate declaration, which is read on input and written on output | as with .smi, the style block and language classes describe presentation; only cue timing and text are carried into other formats |
Pick SAMI as the output
Select .sami in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if SAMI is selectable, the route is real and validated.
Convert on your device
Press Convert. The package is unzipped in memory and its XML content parsed locally; nothing is uploaded.
Verify and download
Each result is signature-checked before the download unlocks, so a failed encode can never masquerade as a valid SAMI file. Outputs keep the original filename with the .sami extension.
SUB to SAMI questions, answered
Will converting SUB to SAMI lose quality?
There is no visual quality to lose — sub is text-oriented and sami is text-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 SUB files here?
Yes — the .sub file is processed inside your browser tab and never uploaded. The package is unzipped in memory and its XML content parsed locally; nothing is uploaded. Close the tab and the file is gone from memory.
Where will the SAMI file work?
Players that read SAMI generally accept .sami as well, though a few match on .smi alone. Novus Convert treats the two identically, running the same hardened SAMI parser — no document types, no external entities, script and style content stripped — and exports any of the twelve timed-text targets.
Will the SAMI file be bigger or smaller than my SUB?
It depends on the content: byte for byte the same format as .smi: <SAMI>, <HEAD> with a <STYLE> block, and <BODY> with SYNC elements. Convert one representative file first and compare before batch-processing a large set.
What happens to the metadata in my SUB file?
In .sub, there is no metadata section; the only header-like content is the frame-rate declaration, which is read on input and written on output. Re-encoding through the browser pipeline does not carry embedded metadata into the output, which doubles as a privacy scrub — check the exported file if you specifically need tags preserved.
Can I convert SAMI back to SUB?
Yes — the reverse route exists as a separate tool. Bear in mind that round-tripping .sub → .sami → .sub is not a perfect undo when any lossy step is involved; keep your original if fidelity matters.