Help
Frequently Asked Questions
Quick answers for every ALTools tool — grouped by feature.
Screen Recorder
Open toolIs anything uploaded?
No. Recording happens entirely in your browser. The video file is saved directly to your device.
Can I record system audio?
In Chrome and Edge, check "Share system audio" when picking a screen. Safari and Firefox may not support tab/system audio.
What format is the download?
Most browsers export WebM (VP9/VP8). Use our Video to MP4 tool if you need MP4.
Merge Audio & Video
Open toolAre my files uploaded to a server?
No. Merging runs entirely in your browser — your video and audio never leave your device.
What formats are supported?
Most common video and audio files work, including clips from phones and cameras. Output is MP4. Turn on compatibility mode if a player cannot open the result.
What if audio and video are out of sync?
Use the "Audio offset" slider to fine-tune alignment by seconds.
Is merging slow?
Usually fast with default settings. Maximum compatibility re-encodes the full video and takes longer on large or HD files.
Merge Videos
Open toolCan I merge TS files?
Yes. You can select multiple .ts segments and merge them into one MP4 output.
Does file order matter?
Yes. Files are merged in list order. Drag items to reorder before exporting.
What if clips have different sizes or codecs?
Matching resolution and codec may concatenate without re-encoding. Mixed sizes or codecs (e.g. AV1/HEVC) are normalized to a single H.264 MP4 — longer exports are normal.
Are files uploaded?
No. Merging runs entirely in your browser.
Trim Video
Open toolCan I remove more than one section?
Yes. Add multiple red segments on the timeline, drag edges to adjust, then export.
What happens to the parts I mark to remove?
Only the unmarked (kept) portions are joined in order into a single MP4. The video is re-encoded, so quality depends on the source and length.
How is this different from Extract Video Clips?
Trim Video marks sections to delete. Extract Video Clips marks sections to keep — better when you only want a few highlights from a long video.
Is my video uploaded?
No. Trimming runs entirely in your browser.
Extract Video Clips
Open toolHow is this different from Trim Video?
Trim Video marks sections to remove. This tool marks sections to keep — better when you only want a few highlights from a long video.
How is this different from Merge Videos?
Merge Videos joins multiple video files. This tool extracts multiple segments from one video and merges them into a single output.
Can I keep multiple non-contiguous segments?
Yes. Add multiple segments on the timeline, drag edges to adjust, and export — kept parts are joined in chronological order.
Is my video uploaded?
No. Extraction and merging run entirely in your browser.
Compress Video
Open toolWill compression reduce quality?
Yes. Lower presets shrink file size more but use stronger compression. Pick a preset that fits your upload limit and how picky you are about detail.
What quality presets are available?
Choose from Very low through Very high, or Original to keep resolution while re-encoding. Enable optional H.265 when your browser supports it for smaller MP4s — some older devices may not play HEVC.
Are files uploaded?
No — compression runs entirely in your browser.
Crop Video
Open toolHow is this different from Trim Video?
Trim Video removes time ranges. Crop Video removes pixels from the frame edges — like cropping a photo.
What happens to resolution and audio?
The export matches your crop box size. Audio is unchanged; only the picture is cropped.
Is my video uploaded?
No. Cropping runs entirely in your browser.
Rotate Video
Open toolWill rotating re-encode my video?
Yes. Rotation changes pixel orientation, so the tool exports a new H.264 MP4. Quality follows your source; very long or high-resolution clips take longer to process.
Which preset fixes sideways iPhone video?
Try 90° clockwise first. If the result is upside down, use 90° counter-clockwise or 180° instead.
Do large files download differently?
On capable devices, exports above about 300 MB to 1 GB (depending on available memory) may ask you to pick a save location and stream the result straight to disk, so the finished file does not have to sit entirely in memory.
How is this different from cropping?
Rotate Video changes orientation. Crop Video removes edges of the frame without turning the picture.
Is my video uploaded?
No. Rotation is processed locally in your browser.
Change Video Speed
Open toolWill changing speed re-encode my video?
Yes. Speed changes adjust timing frame by frame, so the tool exports a new H.264 MP4. Quality follows your source; very long or high-resolution clips take longer to process.
What speed range is supported?
You can export between 0.25× (slow motion) and 4× (timelapse-style) using preset steps.
Does audio change with speed?
By default, audio speeds up or slows down with the picture — pitch rises when faster and drops when slower, similar to a simple speed effect in desktop editors. Turn on Preserve pitch to keep voices and music at a natural tone (available for files under 1 GB).
Do large files download differently?
On capable devices, exports above about 300 MB to 1 GB (depending on available memory) may ask you to pick a save location and stream the result straight to disk, so the finished file does not have to sit entirely in memory.
How is this different from reversing a video?
Speed change keeps frame order but plays faster or slower. Reverse Video plays from end to start.
Is my video uploaded?
No. Speed changes are processed locally in your browser.
Adjust Video Volume
Open toolDoes adjusting volume re-encode my video?
Usually not. ALTools copies the video stream when possible and only re-encodes the audio track to apply the new level. Picture quality should stay close to your source.
Can I mute a video with this tool?
Yes. Choose Mute audio to export volume at 0 while keeping the video track and an audio track in the file.
How is this different from Remove Audio from Video?
Remove Audio strips the audio track entirely. Adjust Volume changes loudness but keeps audio in the file unless you mute it.
What if my video has no audio track?
Volume adjustment only works when the file already includes sound. Add music or voiceover with Merge Audio & Video . To strip audio from a file that still has a soundtrack, use Remove Audio from Video instead.
Will boosting volume fix very noisy recordings?
Boosting makes quiet clips louder, but it also raises background noise and can clip on already-loud peaks. For harsh recordings, lower the level instead.
Do large files download differently?
On capable devices, exports above about 300 MB to 1 GB (depending on available memory) may ask you to pick a save location and stream the result straight to disk, so the finished file does not have to sit entirely in memory.
Is my video uploaded?
No. Volume adjustment runs locally in your browser.
Loop Video
Open toolDoes looping create a seamless crossfade?
No. The tool repeats the full clip back-to-back in order. For a smooth endless loop, start with footage that already matches at the first and last frame.
How is this different from Merge Videos?
Loop Video repeats one file multiple times. Merge Videos joins different files in the order you arrange. Use loop when you want the same clip again; use merge when each segment is different.
How long is the output?
Output duration equals your source length multiplied by the repeat count. A 10-second clip at 5× becomes about 50 seconds. File size grows by roughly the same factor.
Do large files download differently?
When the source is large or the estimated output (source size × repeat count) reaches about 1 GB or more, the tool may ask you to pick a save location and stream the result straight to disk so the finished file does not have to sit entirely in memory.
Should I start from a short clip?
Yes when you can. Shorter sources finish faster and use less memory. Trim unwanted sections with Trim Video first, then loop the part you need.
Is my video uploaded?
No. Looping runs locally in your browser.
Reverse Video
Open toolIs there a duration limit?
Yes — the maximum depends on your device, resolution, and frame count. Many clips up to about 30 minutes at 1080p can be reversed in the browser; very long or very high-resolution sources may hit a lower cap. File size alone is not the limit.
Why do long videos take much longer?
Reversal re-encodes the video. Longer sources are processed in segments so your browser does not run out of memory. Short clips finish quickly; multi-minute or large files need more time — this is expected.
Do large files download differently?
On capable devices, exports above about 1 GB may ask you to pick a save location and stream the result straight to disk, so the finished file does not have to sit entirely in memory.
Is audio reversed too?
When your file includes audio, the audio track is reversed along with the video.
How is this different from changing speed?
Reverse plays frames from end to start. Speed change keeps order but makes playback faster or slower.
Is my video uploaded?
No. Reversal is processed locally in your browser.
Social Media Resize
Open toolWhat platforms are supported?
One-click presets cover TikTok, YouTube Shorts, Instagram Reels, and many more — or set a custom width, height, and frame rate.
Will my video be cropped?
The full frame is kept and scaled to fit. When aspect ratios differ, black bars are added by default. Turn on Blurred background to replace them with a blurred version of your video.
Is processing done locally?
Yes — resize and export to MP4 happen entirely on your device.
Video to MP4
Open toolWhat is Fast-Start?
Fast-Start moves metadata to the beginning of the file so playback can begin before the full download finishes — ideal for web and streaming.
When can I convert without re-encoding?
If your file is already MP4 with H.264 video and AAC audio, choose Fast-Start only — much faster and lossless. Other formats are converted to H.264 + AAC MP4 with Fast-Start enabled.
Are files uploaded?
No — conversion runs entirely on your device.
Video to MP3
Open toolWhat video formats are supported?
Most common video formats work, including MP4, MOV, and WebM from phones and social apps.
What audio do I get?
The tool extracts the primary audio track and exports MP3. Processing time grows with file length and resolution.
Is my video uploaded to a server?
No. Extraction happens entirely in your browser.
Video to Animated Image
Open toolHow long can the segment be?
Up to 30 seconds per export. If frame count exceeds 300, lower the FPS or shorten the segment.
GIF vs animated WebP?
GIF has the widest compatibility. Animated WebP is often smaller with better colors. AVIF offers stronger compression but less universal playback support.
When will animated AVIF be available?
Animated AVIF is marked as coming soon. Browser support for animated AVIF is still limited — use GIF or animated WebP for now.
Is my video uploaded?
No. Conversion runs entirely in your browser.
Video Screenshot
Open toolCan I export many frames at once?
Yes. Use batch export mode to sample up to 60 frames across the video and download them as a ZIP. Stitch mode combines selected capture points into one combined image.
What image formats can I export?
Single frames and stitched images can be saved as JPEG, PNG, or WebP. Batch export packages individual frames in your chosen format inside a ZIP file.
Is my video uploaded?
No. All decoding, capture, and ZIP packaging run entirely in your browser.
Remove Audio from Video
Open toolDoes this remove audio from my video?
Yes. The output is a video file with all audio tracks removed — a silent clip you can post, edit, or remix with new sound.
Is this the same as muting a video?
For most people, yes. Instead of only muting playback in a player, you download a permanently silent file. We export video only and try stream copy first to keep the original picture quality.
Will the video be re-encoded?
Usually not. We try to keep the original video encoding first. Re-encoding to MP4 (H.264) only happens if direct extraction is not possible.
Are files uploaded?
No. Processing happens entirely on your device.
Extract Audio Stream
Open toolHow is this different from Video to MP3?
Video to MP3 always converts audio to MP3. This tool tries to copy the original audio codec (e.g. AAC → M4A, MP3 → MP3) without re-encoding.
When might the audio be re-encoded?
Files over ~1 GB try a fast direct extraction first. If that fails, audio is converted to AAC (.m4a). Smaller files keep the original encoding when possible.
Are files uploaded?
No. Processing happens entirely on your device.
Remove Video Watermark
Open toolDoes this use AI to erase the watermark?
No. It applies a Gaussian-style blur over the area you select. For best results, cover the entire watermark.
Can the blur apply only to part of the video?
Yes. Add timeline segments so the effect runs only on the ranges you need.
Will quality drop?
Only inside the blurred region. The full video is re-encoded to H.264, so longer or higher-resolution files take more time.
Is my video uploaded?
No. Processing runs entirely in your browser.
Add Video Watermark
Open toolText or image watermark?
Both are supported. Text is rendered on your device; PNG with transparency works best for logos.
Can I control placement and timing?
Position and size the overlay box on the preview. Use timeline segments to show the watermark only on selected ranges. Adjust opacity for text or images.
Is my video uploaded?
No. Watermarking runs entirely in your browser.
Subtitle to SRT
Open toolWhich formats are supported?
TXT (.txt), WebVTT (.vtt), ASS/SSA (.ass, .ssa), YouTube SBV (.sbv), and SRT normalization.
Will styling be preserved?
Timing and plain text are preserved. Advanced ASS styles and effects are stripped in the SRT output.
Is my file uploaded?
No. The file is read and converted only in your browser.
Add Subtitle to Video
Open toolAre subtitles burned into the video?
By default, subtitles are added as a selectable MP4 track. Turn on hard subtitle burn-in to render subtitles directly into the video image.
Which subtitle formats are supported?
TXT, SRT, VTT, ASS/SSA, and SBV are supported. The tool normalizes them before adding or burning subtitles.
Is my file uploaded?
No. Video and subtitle processing happen locally in your browser.
YouTube Title Optimizer
Open toolDoes this use AI or upload my data?
No. Analysis runs on your device — your title never leaves your browser.
What makes a good YouTube title?
Clear keywords near the front, roughly 45–65 characters for mobile and search, specific numbers when relevant, and readable formatting without excessive caps.
Can I get title suggestions?
Enter a keyword and topic, then click Generate Variants for SEO-friendly templates you can customize.
YouTube Thumbnail Preview
Open toolWhat image size should I use?
YouTube recommends 1280×720 (16:9). The preview simulates how thumbnails are cropped and scaled in real UI layouts.
Can I customize the title and channel?
Yes. Optional fields let you preview how your thumbnail pairs with title, channel name, views, and publish time.
Is my image uploaded to a server?
No. The image stays in your browser and is only used for on-screen previews.
YouTube Money Calculator
Open toolHow is YouTube money estimated?
Earnings ≈ (views ÷ 1,000) × RPM. RPM is what creators earn per 1,000 monetized views after YouTube's share — it varies by niche, audience country, and season.
What is a typical RPM?
Many channels see roughly $2–$8 RPM. Finance and business can exceed $10; gaming and entertainment are often lower. Use the niche presets as a starting range.
Is this my actual YouTube pay?
No. This is an estimate for planning only. Real revenue depends on monetization status, Shorts vs long-form, memberships, sponsors, and YouTube Analytics.