SRT to SAMI Converter

The SRT to SAMI Converter takes the SubRip file you paste into the SRT Content box - numbered blocks with HH:MM:SS,mmm --> HH:MM:SS,mmm timing lines - and rewrites it as a SAMI (Synchronized Accessible Media Interchange) document. Every cue becomes its own <SYNC> anchor carrying the caption text, saved as a .smi file.

Anyone inheriting an older captioning pipeline eventually meets SAMI. Windows Media Player, kiosk and set-top players, several learning management systems and much archived US broadcast and university material still expect an .smi sidecar, while modern editors export SRT and nothing else. Accessibility and Section 508 teams, e-learning producers and localisation vendors need a dependable srt to sami converter rather than retyping timecodes by hand.

Each block is parsed into start and end times in milliseconds, tolerating comma separators, stray blank lines and inconsistent cue numbering. Because SAMI has no explicit end time - the next <SYNC> start closes the previous caption - the writer is start-anchored, so millisecond start values drive playback. The optional Shift all times by (ms, +/-) field adds its value to both ends of every cue first, so a negative number pulls the file earlier.

Conversion runs inside your browser tab: nothing is uploaded, and feature-length files convert in well under a second.

• Millisecond-accurate SYNC anchors: every SubRip start time is converted straight to the integer millisecond value SAMI expects, so no rounding drift creeps in between the two formats. Timings you see in your editor are the timings that land in the .smi.
• Built-in time shift: the Shift all times by (ms, +/-) field applies a single global offset to both ends of every cue before conversion, which fixes a caption track that runs consistently early or late without a second round trip through another tool.
• Tolerant SRT parsing: the SRT Content parser copes with Windows or Unix line endings, missing trailing blank lines, out-of-order indices and extra whitespace rather than refusing the file.
• Multi-line cues survive: a caption split across two or three display lines stays split in the SAMI output instead of collapsing into one long run of text that overflows the safe area.
• Correct start-anchored model: the converter respects the rule that a SAMI cue ends when the following SYNC begins, so the generated document behaves the way legacy players expect.
• One-click delivery: the finished document can be copied to the clipboard or downloaded directly with the correct .smi extension, ready to sit beside the video file.
• Private by design: the whole convert srt to sami online workflow runs as local JavaScript, so confidential or embargoed programme material never leaves your machine.

1. Open the tool and paste your complete SubRip file into the SRT Content box, or click Load sample if you would rather see the expected input shape before committing your own material.
2. Leave Shift all times by (ms, +/-) empty or at zero when the source timing is already correct against the video.
3. If the captions are known to run late or early, type the correction into Shift all times by (ms, +/-) - for example -500 to bring every cue half a second earlier, or 750 to delay the whole file.
4. Press Run to generate the SAMI document; the output panel fills immediately with the converted markup.
5. Check the first and last <SYNC> anchors in the result against the video to confirm the start times and any offset you applied look right.
6. Use Copy to paste the markup into an existing caption project, or Download to save it as a .smi file.
7. Name the downloaded file to match your video (for example lecture01.smi beside lecture01.mp4) so the player picks the captions up automatically.

Example 1 - a two-cue documentary opening. Converted with Shift all times by (ms, +/-) left at zero.

Input (SRT):
1
00:00:01,000 --> 00:00:04,000
Welcome to the harbour tour.

2
00:00:04,500 --> 00:00:07,200
Our first stop is the old lighthouse.

Output (SAMI):
<SYNC START=1000><P>Welcome to the harbour tour.</P></SYNC>
<SYNC START=4500><P>Our first stop is the old lighthouse.</P></SYNC>

The 00:00:04,500 timestamp becomes the integer 4500: SAMI anchors on milliseconds, not formatted timecode.

Example 2 - a track running a second late. With -1000 in Shift all times by (ms, +/-), cue one is emitted as <SYNC START=0> and cue two as <SYNC START=3500>, so the rhythm of the dialogue is untouched while the file lines back up with the picture.

• Keeps legacy deliverables alive: you can answer a client or archive request for .smi captions in a minute rather than reinstalling a decade-old authoring package.
• Protects accessibility compliance: teams working to Section 508 or institutional accessibility policies can supply the caption format their existing player actually reads, so viewers who need captions are not left without them.
• Removes hand-timing errors: converting timings arithmetically instead of retyping them eliminates the transposed digits that cause a caption to flash at the wrong moment and get a delivery rejected.
• Fixes drift on the spot: a track that is uniformly early or late is corrected during conversion, saving a separate pass through a resync tool before the file goes out.
• Keeps confidential footage private: because the conversion is done locally, unreleased scripts and pre-broadcast dialogue never touch a third-party server.
• Costs nothing per file: there is no per-minute charge or account, so converting a whole back catalogue is as cheap as converting one episode.