Lecture videos, offline: download them on the Mac, watch with subtitles, continue on the iPhone

Why keep a course offline at all

Course videos are the kind you watch in pieces: twenty minutes on the train, ten minutes before bed, the same difficult section three times. Streaming works against that. Every session starts with buffering, a lecture page that has been reorganised or taken down is gone, and subtitles, when they exist, are often only available inside the web player. A local copy with its own subtitle file does not change under you, works with no signal, and can be searched, scrubbed and re-watched as much as you like.

Step 1: get the lectures onto the Mac

1. Copy the address of the lecture page and paste it into the field at the top of Vidnip, then press Return or click Detect. A card appears for each video it finds, with quality options.
2. For a whole course, paste the playlist or collection link instead. Vidnip lists every lecture, lets you tick the ones you want, and saves them as numbered files in a folder named after the playlist, so the order in Finder matches the order of the course.
3. Courses behind a login: click Show Page, sign in in the window that opens, and detection continues.

Step 2: subtitles that actually help

Lectures are where subtitles earn their keep: a second language, a fast speaker, technical terms you want to see spelled out. Vidnip gives you two ways to have them.

• The site's own tracks. If the lecture has subtitles — uploaded by the teacher, auto-generated, or auto-translated — the subtitle button on the video card lists them all. Set a preferred language once in Settings and every download gets that track embedded as a soft subtitle, plus a matching .srt next to the file.
• Generated on the Mac (macOS 26 or later). No subtitles at all? Let the Mac make them. Before downloading, open the same subtitle menu on the card and, under On-device recognition, choose Generate Subtitles On-Device After Download, then the language spoken in the lecture. For a lecture you already have, choose Subtitles › Generate Subtitles (On-Device)… from its right-click menu in Videos. Either way, macOS speech recognition writes a timed .srt next to the video. It runs entirely on the Mac, nothing is uploaded, and it is free and not counted against the trial. The result can also be embedded into the video, so it travels with the file.

Expect the usual speech-recognition slips on names and jargon. The .srt is plain text, so a quick pass in any text editor fixes them.

Step 3: watch in Vidnip, not in a dozen Finder windows

In Vidnip 2.0, click Videos in the sidebar. Every downloaded lecture is there with its cover, length and a thin progress line:

• Double-click to play. The built-in player shows the embedded track and any .srt sitting next to the file; switch between them from the subtitle menu.
• It remembers where you stopped. Close the window mid-lecture and the next double-click continues from there. Right-click to play from the beginning when you want a fresh start. Play it to within the last 10 seconds and it is marked as watched.
• A course stays a course. Group by source (subscription or playlist) and the lectures sit together under the course title; filter to unwatched to see what is left; search by title across everything.
• Formats the player can't open (MKV, WebM) convert to MP4 in place. MKV is usually remuxed in seconds without re-encoding; WebM (VP9) and other codecs the Mac can't decode are converted to H.264, which takes longer.

Step 4: continue on the iPhone

Vidnip for iPhone is the free companion app, and version 2.0 brings the lecture with you:

• Mac › Videos lists the lectures the Mac downloaded, grouped by course, with a Continue Watching row at the top.
• Tap one at home and it streams from the Mac, starting where the Mac stopped. Choose Download to iPhone before you leave and the file is copied over Wi‑Fi — then it plays anywhere, no signal needed, and still starts from your place.
• Your position flows back: pause on the train, and the Mac opens at that spot in the evening. If the phone was offline, the position syncs the next time it sees the Mac.
• Subtitles embedded in the video show up in the iPhone player's subtitle menu, which is why embedding is the safe choice for lectures you want to take along.

Common questions