File Conversion Without a Computer
There was a time when converting file formats required a desktop computer with specialized software. That time is over. Modern smartphones are powerful enough to handle the vast majority of file conversions, from resizing images and converting videos to transforming documents and compressing PDFs.
Whether you are converting a HEIC photo to JPEG to share with a colleague, turning a Word document into a PDF for a client, or extracting audio from a video for your podcast, your phone can handle it. The question is which approach to use: native OS features, browser-based tools, or dedicated apps.
This guide covers all three approaches for both iOS and Android, with specific recommendations for every common conversion scenario.
Native iOS Conversion Features
Apple has built several conversion capabilities directly into iOS. These work without installing any additional apps.
HEIC to JPEG (Automatic)
iPhones capture photos in HEIC format by default, which offers better quality at smaller file sizes than JPEG. But HEIC is not universally supported, especially on older Windows computers and some web platforms.
iOS handles this automatically in most cases:
- Sharing via Messages, Mail, or AirDrop: iOS converts HEIC to JPEG automatically when sharing with non-Apple devices
- Transferring to PC: In Settings > Photos > Transfer to Mac or PC, selecting "Automatic" converts to JPEG during transfer
- Third-party apps: Most social media apps receive JPEG-compatible versions even when the original is HEIC
To always shoot in JPEG instead of HEIC: go to Settings > Camera > Formats and select Most Compatible.
For more details on the HEIC format and manual conversion options, see our guide on converting HEIC to JPG and our HEIC format explainer.
Files App Conversion
The Files app in iOS supports basic conversions:
- Images: Long-press an image > Quick Actions > Convert Image. Choose JPEG, PNG, or HEIF, and select a size (Small, Medium, Large, Actual Size).
- Documents: Open a document, tap the Share button, and select Print. Then pinch-zoom on the print preview to create a PDF.
- Videos: Not natively supported in Files (requires an app or browser tool)
Shortcuts App (Automation)
Apple's Shortcuts app is the most powerful native conversion tool on iOS. Pre-built shortcuts and custom automations can handle complex conversions:
Useful pre-built shortcuts:
- Convert images between formats (JPEG, PNG, HEIF, TIFF, BMP, GIF)
- Convert Live Photos to GIF or video
- Extract audio from video files
- Resize images to specific dimensions
- Create PDFs from multiple images
Example: Batch image conversion shortcut
- Open the Shortcuts app
- Tap + to create a new shortcut
- Add actions: Select Photos (allow multiple) > Convert Image (to JPEG, quality 80%) > Save to Photo Album
- Name it "Batch Convert to JPEG"
- Run from the Shortcuts widget or Share Sheet
iOS Native Conversion Summary
| Conversion | Method | Quality | Ease |
|---|---|---|---|
| HEIC to JPEG | Automatic on share | Excellent | Effortless |
| Image format change | Files app or Shortcuts | Good | Easy |
| Any document to PDF | Print > Pinch to PDF | Good | Easy |
| Live Photo to GIF | Shortcuts | Good | Moderate |
| Video to audio | Shortcuts | Good | Moderate |
| Video format conversion | Not natively supported | N/A | N/A |
| Batch image resize | Shortcuts | Good | Moderate (setup) |
Pro Tip: The iOS "Print to PDF" trick works with almost any file that can be printed. Open the file, tap Share > Print, then pinch-zoom on the print preview with two fingers. iOS creates a PDF that you can then share or save to Files. This works with web pages, emails, documents, and even some app content.
Native Android Conversion Features
Android's open architecture gives it different native capabilities than iOS.
Built-In Features
- Google Photos: Automatically backs up photos in a "Storage saver" quality that converts HEIC, RAW, and other formats to compressed JPEG. Also allows exporting edited photos as JPEG.
- Google Files: The Files by Google app can compress images and clean up storage, though it does not do format conversion.
- Share Sheet: When sharing files to apps like Gmail, Google Drive, or social media, Android may automatically convert formats for compatibility.
Samsung-Specific Features
Samsung Galaxy devices include additional conversion tools:
- Gallery app: Export images in JPEG format regardless of capture format
- My Files: Basic file management with format recognition
- Samsung Notes: Export notes as PDF, Word, or image files
Google Docs Conversion
The Google Docs mobile app can open and convert Office documents:
- Open Google Docs, Sheets, or Slides
- Tap the + button and select a file from your device
- The file opens in Google's editor
- Tap the three-dot menu > Share & export > Save as and choose the output format (DOCX, PDF, EPUB, etc.)
Android Native Conversion Summary
| Conversion | Method | Quality | Ease |
|---|---|---|---|
| HEIC to JPEG | Google Photos export | Good | Easy |
| Document to PDF | Google Docs > Save as PDF | Good | Easy |
| Spreadsheet to PDF | Google Sheets > Save as PDF | Good | Easy |
| Image compression | Google Files | Moderate | Easy |
| Video format change | Not natively supported | N/A | N/A |
| Audio extraction | Not natively supported | N/A | N/A |
| Batch processing | Limited | Varies | Moderate |
Browser-Based Conversion (Both Platforms)
The most versatile approach to mobile file conversion is using browser-based tools. They work on both iOS and Android, require no app installation, and handle formats that native tools cannot.
Using ConvertIntoMP4 on Mobile
Our tools are fully optimized for mobile browsers:
- Open your mobile browser and navigate to the relevant tool:
- Video Converter for video format changes
- Image Converter for image format changes
- PDF Converter for document and PDF operations
- Audio Converter for audio format changes
- Tap Choose File or drag and drop from your Files app
- Select the output format and any options
- Tap Convert
- Download the converted file to your device
Browser-Based Conversion Advantages
| Advantage | Details |
|---|---|
| No installation | Works immediately in any browser |
| No storage usage | No app taking up device space |
| Always current | No updates to install |
| Cross-platform | Same tool on iOS, Android, desktop |
| Wide format support | Hundreds of format combinations |
| Privacy options | Files can be processed and deleted automatically |
Browser-Based Conversion Limitations
- Requires an internet connection
- Upload/download uses mobile data (if not on WiFi)
- Very large files (1 GB+) may be impractical on mobile networks
- Browser tab must stay active during processing on some tools
Pro Tip: Before converting large files on mobile, connect to WiFi to avoid consuming your mobile data allowance. A 5-minute 1080p video can be 500 MB or more, which would make a significant dent in most mobile data plans.
Recommended Mobile Apps
When you need offline conversion or handle files frequently, a dedicated app is the best option.
iOS Apps
Documents by Readdle (Free) A comprehensive file manager with built-in conversion:
- PDF creation from images and documents
- Image format conversion (JPEG, PNG, HEIF)
- ZIP/RAR extraction and creation
- Cloud storage integration (Google Drive, Dropbox, OneDrive)
- Built-in web browser for downloading files
VLC (Free) The legendary media player also handles conversion:
- Convert video between formats (MP4, MKV, AVI, MOV)
- Extract audio from video
- Stream conversion in real-time
- Supports virtually every media format
PDF Expert (Paid) The gold standard for PDF work on iOS:
- Convert images, web pages, and documents to PDF
- Merge, split, compress, and annotate PDFs
- Fill and sign PDF forms
- OCR scanned documents
Android Apps
File Converter (Free, Open Source) A lightweight, ad-free converter that integrates with the Android Share Sheet:
- Image conversion (JPEG, PNG, WebP, GIF, BMP)
- Audio conversion (MP3, AAC, FLAC, WAV, OGG)
- Video conversion (MP4, MKV, AVI, WebM)
- Document conversion (PDF from images)
- Appears directly in the Share menu for quick access
VLC for Android (Free) Same powerful media handling as the iOS version:
- Video and audio playback in all formats
- Stream conversion
- Audio extraction from video
- Network stream support
Adobe Acrobat Reader (Free) PDF operations on Android:
- Create PDFs from photos and documents
- Scan documents with OCR
- Fill and sign forms
- Compress PDFs
- Export PDF to Word or Excel (requires subscription)
App Comparison
| Feature | Documents (iOS) | File Converter (Android) | VLC (Both) | Adobe Acrobat (Both) |
|---|---|---|---|---|
| Image conversion | Yes | Yes | No | No |
| Video conversion | No | Yes | Yes | No |
| Audio conversion | No | Yes | Yes | No |
| PDF creation | Yes | Yes (from images) | No | Yes |
| PDF editing | Basic | No | No | Yes |
| Document conversion | Limited | No | No | PDF export |
| Offline support | Yes | Yes | Yes | Partial |
| Price | Free | Free | Free | Free (basic) |
| Ads | No | No | No | No |
Share Sheet Integration
Both iOS and Android support Share Sheet integration, which lets you convert files without opening a separate app.
iOS Share Sheet Workflow
- Open the file you want to convert in any app (Photos, Files, Mail, etc.)
- Tap the Share button
- Select a conversion app from the Share Sheet (like Shortcuts or a converter app)
- The file is sent to the app, converted, and returned or saved
To add a Shortcuts conversion to your Share Sheet:
- Create a shortcut (e.g., "Convert to PDF")
- Ensure "Show in Share Sheet" is enabled in the shortcut settings
- Select the accepted file types (images, documents, etc.)
- The shortcut appears in your Share Sheet automatically
Android Share Sheet Workflow
- Open any file or select it in a file manager
- Tap the Share button
- Select a conversion app (File Converter, VLC, etc.)
- The app opens with the file pre-loaded for conversion
Apps like File Converter are designed specifically for Share Sheet integration. They appear as conversion options whenever you share a compatible file type, making the workflow nearly seamless.
Common Mobile Conversion Scenarios
Scenario 1: Convert iPhone Photos for Email
HEIC photos from your iPhone may not display correctly when emailed to Windows users or uploaded to older web platforms.
Quick method:
- In the Photos app, select the images
- Tap Share > Mail
- iOS automatically converts to JPEG for email
For more control:
- Use the Files app > Convert Image > JPEG
- Choose the quality/size setting
- Share the JPEG version
Scenario 2: Turn a Document into PDF on the Go
You receive a DOCX file and need to send it as a PDF immediately.
On iOS:
- Open the DOCX in Files or a compatible app
- Tap Share > Print
- Pinch-zoom on the preview to create a PDF
- Share the PDF
On Android:
- Open the DOCX in Google Docs
- Tap three-dot menu > Share & export > Save as > PDF
- Share or save the PDF
Browser method (both platforms):
- Open our PDF converter
- Upload the DOCX file
- Download the converted PDF
Scenario 3: Extract Audio from a Video
You recorded a lecture or interview on video and want just the audio.
Using VLC (both platforms):
- Open VLC and navigate to the video file
- Use the conversion feature to output as MP3 or AAC
- Save the audio file
Browser method:
- Open our audio converter
- Upload the video file
- Select MP3 or AAC as the output
- Download the extracted audio
Scenario 4: Compress a Video for Messaging
Video files are often too large to send via messaging apps.
On iOS:
- Open the video in Photos
- Tap Share > select a messaging app
- iOS offers to reduce the file size automatically
Browser method (both platforms):
- Open our video compressor
- Upload the video
- Select target quality and size
- Download the compressed version
Scenario 5: Create a PDF from Multiple Photos
You need to combine several photos of a document, whiteboard, or receipt into a single PDF.
On iOS (Files app):
- Select multiple images in the Files app
- Long press > Quick Actions > Create PDF
- A multi-page PDF is created automatically
On Android (Google Drive):
- Open Google Drive and tap the + button
- Select Scan to use the camera, or upload existing photos
- Google Drive creates a PDF from the scanned images
Mobile Storage Management
File conversion often intersects with storage management, especially on devices with limited space.
Managing Conversion Storage
| Strategy | iOS | Android |
|---|---|---|
| Delete originals after conversion | Manual (Files app) | Manual (file manager) |
| Offload unused apps | Settings > General > iPhone Storage | Settings > Storage > Free up space |
| Cloud backup before deleting | iCloud, Google Drive | Google Drive, cloud apps |
| Clear conversion cache | Settings > [App] > Clear Cache | Settings > Apps > [App] > Storage |
| Use streaming conversion | Browser tools (no local file) | Browser tools (no local file) |
Checking Available Space
Before converting large files (especially video), check your available storage:
- iOS: Settings > General > iPhone Storage
- Android: Settings > Storage
If space is tight, use a browser-based converter like our video converter or image converter. The conversion happens in the cloud, so you only need space for the output file, not both the input and output simultaneously.
Tips for Reliable Mobile Conversion
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Keep your browser open. If using a browser-based tool, switching to another app or letting your phone lock may interrupt the conversion. Some browsers pause background tabs.
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Use WiFi for large files. Video conversions can involve hundreds of megabytes of upload and download. WiFi is faster, more reliable, and does not consume mobile data.
-
Check the output before deleting the original. Always verify that the converted file is correct (plays properly, looks right, opens without errors) before deleting the source file.
-
Use the right quality setting. Higher quality means larger files. For sharing via messaging apps, medium quality is usually sufficient. For archival or professional use, keep maximum quality.
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Batch when possible. If you need to convert multiple files, use a tool or app that supports batch processing rather than converting one file at a time. Our batch processing guide covers strategies for efficient multi-file operations.
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Mind your battery. Video conversion is CPU-intensive and will drain your battery faster than normal use. Plug in or ensure you have sufficient charge before starting a large conversion.
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Consider privacy. When using online conversion tools, your files are uploaded to a server. For sensitive documents, use an offline app or our privacy-focused converter that deletes files after processing. Our guide on data privacy in file conversion covers this topic in depth.
Platform Feature Comparison Summary
| Capability | iOS (Native) | Android (Native) | Browser Tools | Dedicated Apps |
|---|---|---|---|---|
| Image format conversion | Good (Files + Shortcuts) | Limited (Google Photos) | Excellent | Excellent |
| Video conversion | Limited (Shortcuts) | Not supported | Excellent | Good (VLC) |
| Audio conversion | Limited (Shortcuts) | Not supported | Excellent | Good |
| Document to PDF | Good (Print trick) | Good (Google Docs) | Excellent | Good |
| PDF operations | Basic | Basic (Google Drive) | Excellent | Excellent |
| Batch processing | Shortcuts | Limited | Depends on tool | App-dependent |
| Offline support | Yes | Yes | No | Yes |
| Ease of use | Easy-Moderate | Easy | Easy | Varies |
The best approach depends on your specific needs. For occasional conversions, browser-based tools provide the broadest format support without any setup. For frequent conversions, a dedicated app with Share Sheet integration makes the process seamless. And for simple format changes like HEIC to JPEG, your phone's built-in features often handle it automatically.
Whichever method you choose, the days of needing a desktop computer for file conversion are firmly in the past.
