"This browser cannot read compressed DOCX files"
“This browser cannot read compressed DOCX files.”
What is actually wrong
A .docx is a zip archive with the document XML inside. Because conversions run in your browser and never upload the file, unzipping happens in the browser too, using the DecompressionStream API. Chrome 80, Edge 80, Firefox 113 and Safari 16.4 added it. An older browser, or a locked-down facility build that has not been updated, has no way to open the zip.
Fix it here: DOC transcripts to Premiere JSON
Drop the file. It is detected and converted in your browser; nothing is uploaded. Free to start, no signup.
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Conversions …
Drop EDL, SRT, VTT, .prtranscript, or transcript files
Any caption, transcript or timeline file: CutConvert picks the converter and shows what survives · up to 100 KB per file
The fix, step by step
Update or switch browser
Any current Chrome, Edge, Firefox or Safari works. On a facility machine that cannot be updated, Chrome or Firefox in portable form is enough.
Or save the transcript as .txt
In Word, File > Save As > Plain Text. The TXT to Premiere JSON and TXT to SRT converters read the same transcript layouts without unzipping anything.
Convert
Drop the .docx (in a current browser) or the .txt into the converter. Speaker turns and timestamps are kept either way.
Why a Word file needs unzipping at all
Since Word 2007 the .docx format has been a zip archive. Inside it, word/document.xml holds the text, with separate parts for styles, numbering and media. To read a transcript from it, the converter has to unzip that one entry and parse the XML. On a server that is routine. In a browser it needs the platform to provide decompression, and until recently it did not.
CutConvert moved every conversion into the browser so that files never leave your machine. The trade is that the browser has to be capable of the work. For zip decompression the capability is the DecompressionStream API with the deflate-raw format, which arrived in:
| Browser | Version |
|---|---|
| Chrome and Edge | 80 (February 2020) |
| Firefox | 113 (May 2023) |
| Safari | 16.4 (March 2023) |
Anything newer works. Anything older shows the message at the top of this page.
Where old browsers still turn up
Post-production machines are often frozen on a known-good build for years, and Safari versions are tied to macOS versions, so a Mac on Ventura or earlier without the 16.4 update is the common case. Corporate Windows builds that pin an old Edge are the other. Neither is wrong; they just cannot unzip in the page.
Two workarounds that take a minute
Use another browser on the same machine. Portable Chrome or Firefox runs without installation rights on most locked-down machines, and a current version has everything the converter needs.
Save as plain text. Word’s File > Save As > Plain Text (.txt) writes the same paragraphs, speaker names and timestamps without the zip wrapper. The TXT to Premiere JSON and TXT to SRT converters read those layouts directly. Formatting is lost, but transcript formatting is rarely what you need to keep.
Other DOCX messages
"DOCX file does not contain word/document.xml" means the file is a zip but not a Word document, usually a renamed .zip or a Pages export. "DOCX compression method is not supported" means the archive used a method other than deflate, which Word itself never does; re-save from Word. "Legacy .doc files are not supported" is the older binary Word format; save as .docx or .txt.
Every conversion here still runs locally. The workaround changes the file format, not where the work happens.
FAQ
- Why not just upload the file to a server?
- Because the point of CutConvert is that files never leave your device. The conversion needs your browser to do the unzipping, and current browsers all can.
- Which browser version do I need?
- Chrome or Edge 80, Firefox 113, or Safari 16.4 and later. Anything current is fine.
- Does saving as .txt lose the speaker names?
- No. Speaker names and timestamps are text and survive. Only bold, italics and layout are dropped, and the converters do not use those.