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About this tool
Generate consistent, sortable video file names across course modules and lessons, with padding, case style and length checks.
Course Video Naming Builder converts a module-and-lesson outline into one consistent, zero-padded file name per lesson using a pattern you control. It slugifies titles into kebab, snake or Pascal case, strips the characters Windows forbids in a file name, keeps every name inside the 255-byte per-name limit used by ext4, APFS and NTFS, and flags duplicates and reserved device names such as CON or LPT1. Built for course creators, editors and VAs who need raw footage, edits and uploads to sort in teaching order on any machine.
Open Course Video Naming Builder on AltFTool — it loads instantly in your browser.
Paste your outline into the 'Course outline (module lines, lessons indented or bulleted)' textarea and set the Course code.
Edit the Naming pattern — it starts at {course}_M{mm}_L{ll}_{lesson} — or tap a token button such as {gg} or {module}, then pick a Case style (kebab-case, snake_case or PascalCase), a File extension and Number padding (digits).
Check the Longest name row against the 255-byte limit along with the Duplicate names and Warnings counts, then press Copy names to take one file name per lesson.
Zero-padded numbers keep lesson 2 ahead of lesson 10 in every file manager and upload queue.
Removes the < > : " / \ | ? * characters Windows rejects and warns about reserved device names.
Change the pattern once and every lesson in the course is renamed to match.
Use a fixed pattern that puts sortable numbers before free text, such as COURSE_M01_L03_topic-title.mp4. Zero-pad module and lesson numbers to at least two digits, use hyphens or underscores instead of spaces, and keep the same pattern for raw footage, edits and final uploads so files line up side by side.
Because file managers sort names as text, not numbers, so "10" comes before "2". Zero-padding fixes it: 01, 02, 10, 11 sort correctly as plain text. Two digits covers up to 99 lessons; use three if a module could exceed that.
Avoid < > : " / \ | ? * and control characters — Windows rejects all of them — plus leading or trailing spaces and dots. Also avoid the reserved device names CON, PRN, AUX, NUL, COM1-COM9 and LPT1-LPT9, which cannot be used as a file name even with an extension.
A single file name is limited to 255 bytes on ext4 and 255 characters on APFS and NTFS, and the full path is capped separately (260 characters on Windows unless long paths are enabled). Non-Latin scripts such as Chinese, Japanese, Korean, Cyrillic or Arabic are kept as-is in the generated name and use two to four UTF-8 bytes per character, so a name that looks short can still hit the limit. Accented Latin letters such as é, ü or ñ are normalised to their unaccented base letter (e, u, n) in the generated name, so they do not add extra bytes.