Alter Convert icon

Alter Convert
Pro · Fast · Easy

The all-in-one professional media converter. Convert video, audio, images, and PDFs, extract audio, and play anything — entirely offline and private.

40+ Formats 100% Offline & Private Free to Use
Download on the App Store

Everything you need for media conversion

From 4K video to lossless audio — one app does it all.

🎬

Video Conversion

Convert between MP4, MOV, MKV, AVI, WMV, FLV, MPEG, MPG, WEBM, ASF, VOB, M4V, OGV, TS, 3GP, 3G2. Supports 4K & 2K Ultra HD with original quality preserved, plus trimming and video-to-GIF conversion.

4K & 2K HD Video Trimming Video to GIF
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Audio Conversion

Convert MP3, AAC, M4A, OGG, WAV, FLAC, WMA, CAF, OPUS, AIFF, MKA, OGA, WV, SPX, MP2 with lossless quality. Extract audio from any video in one tap, with trimming support.

Lossless FLAC ↔ WAV Audio Extraction Audio Trimming
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Image Conversion

Convert between JPG, PNG, JPEG, WebP, BMP, TIFF, and HEIC. Batch process multiple images with one tap, and convert between PDF and images.

7 Formats Batch Images PDF ↔ Image
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PDF Processing

Convert PDFs to images and images back to PDF. Handle documents alongside your media files — all in one app.

PDF ↔ Image Document Conversion
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Batch Processing

Select multiple files at once for one-tap batch conversion. Mix video and audio files together — the queue runs automatically so you don't have to wait.

Mixed Formats Auto Queue
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Universal Player

Play almost all mainstream video and audio formats directly in the app. Instant preview of converted files — no extra player needed.

Smooth Playback Instant Preview
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Simple & Intuitive

Just three steps: Select file → Choose format → Start conversion. Clean interface, no registration needed, open and use immediately.

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Privacy & Security

All conversion happens locally on your device. No files are uploaded to the cloud, no data is collected or stored. Your privacy is fully protected.

Convert in three easy steps

1

Select File

Pick a video or audio file from your device. Supports all major formats.

2

Choose Format

Pick your desired output format from 40+ options. Adjust quality if needed.

3

Convert

Tap convert. Done in seconds — all processed locally on your device.

40+ formats covered

From HD video and lossless audio to images and PDFs — we support them all.

Video Formats (16)

MP4MOVMKVAVIWMVFLVMPEGMPGWEBMASFVOBM4VOGVTS3GP3G2

Audio Formats (15)

MP3AACM4AOGGWAVFLACWMACAFOPUSAIFFMKAOGAWVSPXMP2

Image Formats (7)

JPGPNGJPEGWebPBMPTIFFHEIC

Documents (1)

PDF

Made for real-world needs

🎞️

Batch Extract Audio

Extract background music from videos and save as MP3, AAC, or any audio format in batch.

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Device Compatibility

Convert video formats for seamless playback on iPhone, iPad, TV, and other devices.

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Audio Extraction

Extract memorable audio clips from movies, music videos, and concerts in lossless quality.

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Format Problems Solved

Batch process all your video files to solve format compatibility issues at once.

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Lossless Audio

Convert between FLAC and WAV with zero quality loss — perfect for audiophiles.

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28 Languages

Fully localized in 28 languages including English, Chinese, Japanese, Korean, French, German, and more.

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Your files never leave your device

All conversion processing happens locally on your iPhone or iPad. No files are ever uploaded to any server. We don't collect, store, or have access to your media files — your data is yours alone.

Ready to convert?

Free. Private. No sign-up needed. Download now and start converting in seconds.

Download on the App Store

Compatible with iPhone & iPad • iOS 15+ • Free