Subtitle Encoding Converter

The Subtitle Encoding Converter takes the raw text of an SRT file and rewrites its character data in one of two ways: Unicode NFC normalisation, or a reduction to plain ASCII. You paste your captions into the SRT Content box, pick a mode in the Target menu, and get back a complete SRT file - same cue numbers, same timecodes, same line breaks - with only the characters themselves changed. The result downloads as a .srt file ready to drop straight back into your player, encoder or delivery folder.

Mojibake is the everyday name for the problem this solves: a Polish translator sends back a file full of accented letters, a legacy set-top box or an old hardware player renders them as question marks or boxes, and the client rejects the delivery. Localisation vendors, e-learning teams captioning multilingual courses, and anyone archiving subtitles collected from many contributors all run into the same mismatch. A quick pass through a subtitle encoding converter online is usually faster than diagnosing which of five tools in the chain mangled the text.

Technically, the NFC option calls Unicode Normalization Form C, which composes a base letter plus a combining mark into the single precomposed code point that most fonts and players actually have a glyph for. The ASCII option strips every character above U+007F, but first substitutes the typographic punctuation that translators habitually leave in: curly single and double quotes become straight quotes, en and em dashes become a hyphen, and a horizontal ellipsis becomes three dots. Anything else non-ASCII is removed rather than guessed at, so no character is silently replaced with a wrong one.

Nothing is uploaded. The conversion runs entirely in your browser on the text you pasted, so confidential scripts and pre-release episode captions never leave your machine, and even feature-length files of several thousand cues normalise in well under a second.

• Two clearly separated modes: The Target select gives you NFC normalisation for modern Unicode players and an ASCII-only strip for legacy hardware. Choosing the wrong one is easy to undo because the original text stays in the input box.
• True NFC composition: Decomposed sequences such as a bare letter followed by a combining acute accent are folded into the single precomposed character, which is what most subtitle renderers and font subsets actually contain.
• Smart punctuation mapping: Before stripping, the ASCII mode converts curly quotes, en dashes, em dashes and the ellipsis character into their ASCII equivalents, so sentences stay readable instead of losing their punctuation entirely.
• Timing is never touched: The tool operates on the file as text without reparsing cue boundaries, so every timestamp, cue number and blank-line separator comes out byte-identical apart from the characters you asked to change.
• Whole-file operation: Paste an entire episode or a whole season compilation into the SRT Content box; there is no cue limit and no need to split the file into chunks.
• Immediate .srt download: The output is a finished subtitle file, not a report, so you can save it and hand it straight to an encoder or a client without an intermediate copy-and-paste step.
• Fully client-side: No account, no upload and no server-side storage - the normalisation happens in the page you are already looking at.

1. Open the tool and click Load sample if you want to see how a file with accented and typographic characters behaves before you commit your own.
2. Paste the full contents of your subtitle file into the SRT Content box, including cue numbers and timecodes - do not paste only the dialogue lines.
3. Choose your mode in the Target menu: pick NFC when the file is going to a modern player, streaming platform or editing suite, and pick the ASCII option only when a legacy device genuinely cannot display Unicode.
4. Run the tool and read the output pane, checking a couple of the lines you know contained accents, curly quotes or dashes to confirm they came through the way you expected.
5. Compare the cue count and the first and last timecodes against your source to reassure yourself that only characters changed.
6. Copy the result, or download it as a .srt file and test it in the target player before sending the delivery.

Example 1 - accented French returning from a translator. The file looks correct in one editor and broken in another because the accents are stored as decomposed sequences. NFC composes them into single code points.

Before (decomposed e + combining acute)
2
00:00:04,500 --> 00:00:07,200
L'equipe a de'ja termine' le tournage.

After (Target: NFC)
2
00:00:04,500 --> 00:00:07,200
L'equipe a deja termine le tournage.

Example 2 - preparing a file for an old hardware player. The ASCII mode keeps the sense of the punctuation instead of deleting it.

Before
5
00:01:12,000 --> 00:01:15,000
"It's fine," she said - eventually...

After (Target: ASCII)
5
00:01:12,000 --> 00:01:15,000
"It's fine," she said - eventually...

Curly quotes became straight quotes, the en dash became a hyphen and the single ellipsis character became three dots, so the line still reads naturally on a device that has no Unicode font.

• Stops rejected deliveries: Broadcasters and platforms routinely bounce files that render as boxes or question marks, and a single normalisation pass removes the most common cause before you submit.
• Saves diagnostic time: Instead of tracing which editor, FTP client or transcoder corrupted your text, you fix the file directly and move on with the job.
• Keeps legacy hardware in play: Venues, kiosks and older set-top boxes that cannot show Unicode still get readable captions rather than a line of blanks.
• No risk to your sync: Because timings are untouched, you never have to re-check the whole episode against picture after converting.
• Protects confidential material: Embargoed scripts and unreleased episode captions stay on your machine because nothing is transmitted anywhere.
• Costs nothing and needs no install: There is no software to approve with IT, which matters when you are working from a client site or a locked-down laptop.