HermitFile Pro

Reframe a video, panning the crop to follow the motion

Crops into a new aspect ratio the way a camera operator would reframe a shot — the crop window pans to follow motion and detail instead of sitting locked to the centre. Runs entirely on this device. The original audio comes along unchanged if it's AAC.

Drop a video hereTap anywhere in this box
MP4, MOV, MKV, WebM — anything your browser can read. Any length: there is no upload, so there is no limit.

Nothing is uploaded. Open your browser’s Network tab while you convert — you will see the file go nowhere.

Reframe settings

The starting-frame preview updates as you adjust these — the real tracking runs across the whole clip when you convert.

What you'll get back

Worked out from this actual file and this actual browser, before anything is written.

Range and frame rate

Your video

No AI model — motion and detail, measured directly

Every output frame is drawn onto a tiny 64-pixel-wide analysis canvas, where two things are measured directly: how much each pixel changed since the frame before (motion), and how much it differs from its neighbours (edge detail). The weighted centre of that combined signal is where the crop wants to point. There's no face detector or machine-learning model doing the deciding, the same way Green Screen keys a colour rather than segmenting a subject with a model.

Why the pan doesn't jitter

A raw per-frame focus point is noisy on its own. It's smoothed with a fixed 0.35-second time constant, independent of frame rate, before the crop window is placed — that's what turns a twitchy estimate into a steady pan. The Tracking slider then blends between that smoothed point and the frame's plain centre, so a lower setting falls back toward an ordinary fixed crop if the tracking picks the wrong thing.

Why the audio sometimes doesn't survive

The video is genuinely re-encoded, because building the tracked crop means drawing new pixels — there is no wrapper trick for that. Audio doesn't need to be, so it's copied across as compressed packets exactly like the site's other video tools do, provided it's AAC. Anything else would need a decoder and an encoder this tool doesn't carry, so it's dropped rather than silently guessed at, and the plan says so before you convert anything.

Nothing is uploaded

Decoding, measuring motion, drawing the tracked crop and video encoding all happen in this page. There is no server here to send the video to, and the page's security policy blocks any connection to anywhere but this site. Here is how that is enforced.

How to auto-reframe a video

  1. Drop the video in. Nothing is sent anywhere — the whole file stays on this device.
  2. Pick a target aspect ratio and adjust Tracking until the plan and preview look right.
  3. Set the range, output size and frame rate, then press Convert and download.

All 39 HermitFile tools

Every one of them runs in your browser. Nothing you open is uploaded, and nothing is stored.

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Video tools

MOV to MP4Turn an iPhone .mov into an .mp4 by swapping the wrapper, with the video copied across and nothing re-encoded. Trim a videoKeep the part you want. The clip is copied rather than re-encoded, so no quality is lost. Split into partsCut a long recording into pieces short enough to post, without re-encoding any of them. Rotate a videoChange the rotation flag a phone wrote instead of re-encoding the picture. Seconds, not minutes. Remove the soundDrop the audio track and copy every frame across untouched — same quality, same size. Video to MP3Convert a video’s sound to MP3, or lift the original audio out byte for byte with nothing re-encoded. Video to GIFPick a range, a frame rate and a size, and get an animated GIF back with nothing uploaded. Green screen swapSwap a green or blue screen for a solid colour with a live preview, no AI model and no watermark. Silence removerFinds the quiet stretches by listening to the audio and cuts them out, with a timeline showing every cut first. Blur pad to a new ratioFit a video into 9:16, 1:1 or another shape with a blurred background instead of black bars. Compress a videoAim at a Discord, email or WhatsApp limit — or your own — and get an MP4 checked afterwards, not just promised. Noise removerLearns your recording’s own background hiss or hum from a quiet stretch, then subtracts exactly that. Auto-reframeCrops into a new aspect ratio with the crop panning to follow the motion, instead of a fixed centre. CaptionsBurns an .srt or .vtt subtitle file into the video as styled, timed on-screen text. Beat syncFinds the beats in the clip's own audio and lands a flash or a zoom-punch on each one. Highlight finderScores a clip by loudness and movement, and ranks the best stretches to cut out, losslessly.

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