Enter target size
Suitable for email attachments, Discord, form uploads, and platform size limitations.
VIDEO TOOLS
Edit video in your browser.
Choose a task, add a video and start. No account or setup first.
Free · Local processing
Compress video to a target file size
Enter 10 MB, 25 MB or any target size, the system automatically calculates the appropriate video bitrate and outputs MP4 with good compatibility.
File will not leave the device
Compression complete
Calculate bitrate automatically
Allocate picture bit rates according to video duration and audio bit rate, without understanding complex parameters.
Locally generated MP4
The processing occurs in the browser, preventing private videos from being uploaded to third parties.
Creator tools
Change video aspect ratio
Reconstruct horizontal screen material to 9:16 used by TikTok, Reels, and Shorts, and also output 1:1, 4:5, and 16:9.
Do not upload original video
Aspect ratio conversion complete
Vertical screen short video
Suitable for YouTube Shorts, TikTok, Instagram Reels.
Information flow advertising
Obtain a larger visual area in the mobile phone information flow while retaining the main screen.
Horizontal publishing
Suitable for YouTube, website embedding, presentations, and TV broadcasts.
Professional quality inspection · Local scanning
Video preflight
Before publishing, scan for black or white frames, frozen shots, long silences, audio clipping, shot pacing and letterboxing. Review issues in a timestamped report.
The original video is not uploaded
—Comprehensive score
Preflight report
Publish Risk Overview
Scoring is used to quickly locate abnormalities and does not replace manual film review.
Find issues faster
Sample brightness, frame differences and audio levels over time to locate potential issues.
Jump to each issue
Select an issue in the report to review that moment in the source video.
Export for your workflow
Export a structured JSON report for review, records or later analysis.
Perceptual fingerprint · No need to upload
Duplicate segment detection in two videos
Even if the video is recompressed, the resolution is changed, or slightly cropped, it can still find the same consecutive segments according to the perceptual screen fingerprint, and mark the precise interval in the two videos.
Local comparison content
%
sec
sec
Content fingerprint
Continuous similar segments
Perceptual frame fingerprint
Compares frame structure rather than file bytes, so similar content can still be found after re-encoding and changing resolutions.
Full-frame and center fingerprints
Simultaneously calculate the complete frame and the center area to enhance tolerance to slight cropping, border and watermark changes.
Locate the continuous interval
Instead of just saying "similar", give the respective start, end and offset times of videos A and B.
Dynamic sidechain compression
Narration automatically lowers background music
Upload a video with human voice and a background music. The music automatically lowers when speaking is detected and resumes naturally when there is a pause, without the need to manually draw volume keyframes.
Native FFmpeg mixing
dB
ms
ms
Fast mode will not reduce the image quality; if the original video encoding cannot be loaded into MP4, please use "compatibility mode" instead.
Voiceover mix complete
Side chain compression
Use the narration track as the control signal to dynamically lower the music only when the vocal appears.
Music automatically loops
If the background music is shorter than the video, it does not need to be edited in advance. It will automatically loop until the end of the video.
Say goodbye to manual animation keyframes
Interviews, narrations, lessons, and short video narrations can all be done in one go for basic mixing.
LOCAL · FREE
Video storyboard contact sheet
Sample a video at evenly spaced times, make a timestamped frame sheet and jump back to any frame.
Video stays on this device
Drop a video here
or choose a file your browser can play (up to 128 MiB)
Contact sheet
Jump to a sampled frame
Privacy by design
Your materials do not need to be handed over to others first.
ToolRobin uses WebAssembly in the browser to run the video engine. The original video, subtitles and processed results only exist on the current device by default.
Video processing does not go through ToolRobin servers.
After closing the page, the temporary files in the browser are released.
Local computing reduces server transcoding costs and is suitable for free tool stations.
FAQ
Frequently asked questions
The browser video engine is downloaded the first time a video is processed and is cached by the browser thereafter.
First run requires downloading approximately 31 MB of the FFmpeg WebAssembly engine. Modern browsers often cache the download after it is complete, making subsequent use faster.
Files and text are processed in your browser, without uploading your input.
The tool calculates the average bit rate by duration, but the complexity and packaging overhead of different pictures will cause a small amount of deviation. When a tight cap is needed, set the target 5% to 8% below the platform limit.
Browser processing consumes device memory and CPU. The desktop version is more suitable for processing longer videos; the mobile version is recommended to use shorter footage. The browser version of FFmpeg is generally slower than the desktop native software.
Free browser video tools
ToolRobin Video Tools helps creators review and prepare footage directly in the browser. Build a timestamped contact sheet from evenly sampled frames, reframe clips for social formats, compare footage and run preflight checks without installing a desktop editor.
Review a long clip at a glance
Choose 12 to 48 evenly spaced frames, inspect the contact sheet and jump back to a frame time in the source video. Short shots between samples may be missed.
Privacy-first workflow
The contact sheet is generated on your device. Video is not uploaded; the browser must support decoding the file.