Free Video Splitter

Worked example

Press "Try a sample". The tool records a 12-second clip, sample-video.mp4 (or .webm in a browser that can only record WebM), and the file chip shows its size and "0:12 · 640×360". "How to split" starts on "Every N seconds" with 60 chosen, so the plan line says "1 part of about 0:12". Type 5 in the "Other:" box and it changes to "3 parts of about 0:05", because 12 seconds in 5-second pieces is 5, 5 and 2. "Cutting" is "Exact" in this mode. Press "Split video". The page says "3 parts are ready." and lists "Part 1 0:00–0:05", "Part 2 0:05–0:10" and "Part 3 0:10–0:12", each with its size and a "Save" button. "Download all as ZIP" gives sample-video_parts.zip. Now press "Equal parts": "Cutting" switches to "Fast" and the plan reads "2 parts of about 0:06".

Which settings to use, and the limits

• Choose how to split first. "Every N seconds" has buttons for 0:15, 0:30, 1:00, 1:30, 3:00 and 10:00, or type a number of seconds from 1 in "Other:". The last part is whatever is left, and a leftover under 1 second is folded into the part before it. "Equal parts" takes 2 to 200. "Under a size" has buttons for 10, 16, 25, 50, 100 and 500 MB, or type your own from 1 MB. The tool never makes more than 200 parts; if "Every N seconds" would need more, the last part runs to the end of the video.
• Choose "Fast" or "Exact" on purpose. "Fast" copies the picture and sound without re-encoding, so there is no quality loss and it takes seconds. Each cut lands on a keyframe at or after the time, so a part can run long, and the tool can make fewer parts than planned. It keeps the original container, such as .mov or .mkv. "Exact" re-encodes so cuts land on the second: H.264 (CRF 21) with AAC at 128 kbps in an .mp4, or VP8 with Opus at 96 kbps for a WebM source. "Every N seconds" starts on "Exact", because a part that runs 2 seconds over breaks a 60-second limit. The other two modes start on "Fast".
• Let "Under a size" split again when a part is too big. The tool assumes an even bitrate and aims at 90% of your limit, so a 360 MB file with a 25 MB limit becomes 16 parts. A file already under the limit gives one part. Video is never even, so after the run the tool checks the biggest part and, if it is over, splits again into more parts, up to three tries in all. If a part is still too big you see "A part is still over the size limit. Try a smaller limit or Exact cutting." and the parts are kept for you. Here 1 MB means 1,048,576 bytes.
• Save parts one by one, or all in a ZIP. When the split ends, each row has a play button ("Part 1", "Part 2" and so on) that loads that part in the player, its time range and size, and a "Save" button. With more than one part, "Download all as ZIP" appears. The ZIP is stored without compression and named like holiday_parts.zip. Parts are named like holiday_part03.mp4, with the number padded to at least two digits. All the parts are built in the browser's memory before any can be saved, which is why the file limits below apply.
• Know the file limits. The tool takes one video at a time, such as MP4, MOV, MKV, WebM, AVI, M4V, 3GP, TS or MTS. It refuses a file above about 2 GB on a normal computer, 1 GB on a computer reporting 4 GB of memory or less, and 400 MB on a phone, with "This file is 2.6 GB, which is too large to process in your browser on this device (limit ~2 GB). Try a smaller file or trim a shorter clip first." Cautions start at 800, 400 and 150 MB. The video is normally read from disk, not copied. The engine, about 31 MB, downloads on first use. Nothing is uploaded.
• Check the length line on unusual formats. The length comes from the browser's own player when you add the file, and the plan line, such as "3 parts of about 0:05", appears once it is known. For formats the browser cannot play, such as some AVI and MKV files, there is no plan line; the tool then reads the length from the engine's log when you press "Split video". A WebM recorded in a browser may report no length at first, and the tool seeks to its end to find it. Only the first picture track and the first sound track are kept; other audio tracks and subtitles are left out.

Common problems and how to fix them

It says "The length of this video could not be read, so it cannot be split. Save it again from your phone or editor (or convert it to MP4 first), then try again."

The tool needs the total length to place the cuts. It asks the browser's player first and, if that fails, reads the length from the engine's log when the split starts. If neither gives a length, this message appears and nothing is cut. Re-save the video from the app that made it, or convert it to MP4 in the Video Converter, then add it again.

It says "Something went wrong while processing this file. Try a different output format or a different source file."

The split ended without writing any part, and the engine gave no clearer reason. "Cutting" is the setting to change, since there is no output format to pick. "Exact" has to decode the video and re-encode it, so it fails on pictures the in-browser engine cannot decode, and AV1 is one known case. "Fast" copies without decoding, so try it. If "Fast" fails, try "Exact", which writes a fresh MP4. Also try the original file again if it came from a download that may have been cut short.

The big button said "Splitting 40%… (tap to cancel)" and the split stopped, with no parts and no message.

That button is the Cancel button. While a split runs, the same wide button shows the progress and cancels the run when pressed, which is easy to do by accident on a phone. A cancel ends the engine and drops the half-finished parts without any message. Press "Split video" again. The engine is loaded again, which is quick because the browser keeps it. During the first load the button reads "Loading the engine… (tap to cancel)" and works the same way.

It says "This file changed or moved after you picked it — please choose it again."

The video is read from disk while it is being split, not copied first, so the file must still be there and unchanged. Moving, renaming or deleting it, or saving over it from another program, breaks the read. Add the file again from where it is now. If the page instead says a file "could not be read" and names it, the file failed even when it was added, which is typical of a cloud-only file from Google Photos, iCloud or a cloud drive. Save it to this device first.

It says "A part is still over the size limit. Try a smaller limit or Exact cutting."

This shows above the parts when "Under a size" could not get every part under your limit after three tries. The parts are still made and can be saved. "Fast" cuts only at keyframes, so part lengths and sizes vary. "Exact" cuts on the second, so parts do not run long. A smaller limit also makes more, smaller parts. If a hard limit matters, check each part's size in the list before you send it.

How it compares

This tool cuts one video from start to end into consecutive parts, by length, by count or by size. It cannot keep one section or leave a section out; the Video Trimmer does that. "Fast" is a stream copy, so it is quick and lossless but cuts only at keyframes. "Exact" re-encodes at fixed settings, with no quality or bitrate control. Parts are built in browser memory, so a file over about 2 GB on a normal computer, or 400 MB on a phone, needs software on your computer instead. It keeps only the first picture and sound tracks. In exchange there is nothing to install, and the video stays in your browser.