I regularly convert PDFs, images, videos, audio files, and documents, but choosing the right file converter is confusing. I’m looking for a reliable cheat sheet that matches common file formats with the best conversion tools.
Build the cheat sheet around file type, not a single “universal” converter: PDFs and Office files, use Acrobat or LibreOffice; images, ImageMagick; video and audio, FFmpeg; easier video jobs, HandBrake; ebooks, Calibre; archives, 7-Zip. Keep conversions local when files contain private data. The main catch is PDF-to-Word conversion: no tool can perfectly restore complex layouts, and scanned PDFs need OCR before they become editable.
The hidden trap is that changing the extension is not the same as converting the file. Check whether you need smaller size, wider compatibility, or editable content first, because the “best” tool and output format depend more on that goal than the source format.
Uploading everything to a browser-based converter can create a privacy problem, especially with contracts, tax forms, medical records, or client files. Before picking a tool, decide whether the file can safely leave your computer. That matters even more than convenience.
My rough cheat sheet is: LibreOffice for DOCX, ODT, XLSX, and PDF export; HandBrake for straightforward video conversions; FFmpeg for unusual video or audio formats and batch jobs; Audacity when audio needs editing as well as conversion; and GIMP or ImageMagick for images. For PDFs, use a proper PDF editor when preserving layout matters. If the PDF is a scan, you need OCR rather than a normal PDF-to-Word conversion.
@0xserver6 is right that the target format depends on the goal, but quality loss deserves equal attention. JPEG, MP3, and many video formats are lossy, so repeated conversions gradually make the file worse. Keep the original, convert from that each time, and avoid online “universal” tools for anything sensitive or difficult to replace.
Moving an H.264 video from MKV to MP4 is a very different job from converting HEVC video to H.264, even though both may be described as “video conversion.” The first can often copy the existing streams into a new container in seconds with no quality loss. The second requires re-encoding, takes longer, and may reduce quality. That distinction belongs near the top of any cheat sheet.
I’d organize it by what must survive the conversion:
- Text and basic document formatting: LibreOffice for Office formats, Pandoc for Markdown, HTML, EPUB, and other text-focused documents.
- Exact page appearance: export or print to PDF. Going back from PDF to an editable document is inherently less reliable.
- Scanned pages: OCR first, then correct the recognition errors manually.
- Photos: use an image editor for a few files and ImageMagick for batches. PNG suits graphics and screenshots, while JPEG or WebP usually makes more sense for photos.
- Vector artwork: use a vector editor such as Inkscape. Converting SVG to PNG creates a fixed-size image, so keep the SVG original.
- Video compatibility: HandBrake is convenient when re-encoding is actually needed. For container changes, stream copying, subtitles, or unusual formats, FFmpeg gives much more control.
- Audio listening copies: AAC, MP3, or Opus depending on device support. For editing or archiving, keep WAV or FLAC rather than repeatedly converting compressed files.
- Ebooks: Calibre handles most ordinary format changes, but complicated tables and page-based layouts still tend to need cleanup.
- Archives: 7-Zip is fine for extracting and repacking, but archive conversion does not repair damaged files or bypass encryption.
@corelynx is right about renamed extensions, but there is a middle case between renaming and full conversion: remuxing. That is especially useful with MP4, MKV, M4A, and similar containers. A converter that always re-encodes can waste time and degrade a file that only needed different packaging.
The other overlooked issue is everything surrounding the main content. Converters may drop subtitles, chapter markers, transparency, animation, comments, tracked changes, embedded fonts, color profiles, EXIF data, or timestamps. A file opening successfully does not prove the conversion was complete. For anything important, compare the page count or duration, check a few points throughout the output, and confirm that the features you care about are still there.
So my “right tool” rule would be: use the simplest program that understands the source properly, supports the required destination, and lets you avoid re-encoding when possible. Keep the source file until the converted copy has been checked. That prevents more trouble than finding a supposedly universal converter.
The source application’s own Export or Save As command should be at the top of the cheat sheet. If the file was created in Word, Photoshop, Blender, PowerPoint, or another specialist program, that program usually understands its own fonts, layers, effects, links, and settings better than a generic converter does.
People get burned by files that contain behavior rather than plain content. An XLSX may have formulas, macros, external data connections, or validation rules. A presentation may have animation, video, speaker notes, and custom fonts. A PDF may contain forms, signatures, bookmarks, or accessibility tags. The converted file can look fine on page one while half of that functionality has quietly disappeared. “It opens” is a very low bar.
My order would be simple: try native export first, then a dedicated converter, then a general-purpose tool, and use an online converter only when the file is disposable or non-sensitive. Print to PDF belongs near the bottom. It is handy when you only need something that looks printable, but it often flattens interactive elements and can produce a less useful PDF than a proper export.
The destination program matters too. Do not convert to WebP because it is efficient if the recipient’s old software cannot open it. Do not send an Opus audio file to someone whose playback system expects MP3. Do not convert a document to PDF/A unless an archive or agency actually requires it. The best format is the one that survives the recipient’s real workflow, not the format with the nicest technical description.
For important jobs, make a small test conversion before feeding hundreds of files into a batch. Open the result in the actual target app and check the parts most likely to fail: fonts, formulas, page breaks, transparency, subtitles, forms, links, and metadata. @devfalcon4190 covered checking surrounding content, but interactive features deserve a separate warning because they can vanish without any obvious visual error.
So the practical cheat sheet is less about memorizing one tool per extension. Use the creating application when available, use specialist tools when changing media structure or format, and test against the software that will consume the result. Keep the original. Never overwrite it during conversion. That last rule saves more files than any “universal converter” ever will.
Don’t let the tool pick its own quality settings and assume it made a sensible choice. That’s where most people quietly ruin files without realizing it. Half the ‘this converter is bad’ complaints I’ve seen come down to a default bitrate, a default JPEG quality slider sitting at 80, or a resize that snuck in because a preset assumed a target device. The tool wasn’t wrong. Nobody checked what it was told to do.
The remux point from @devfalcon4190 is the most useful thing in this whole thread, and it deserves more weight than the tool list. Stream copying an H.264 track from MKV into MP4 costs you nothing and takes seconds. If your converter re-encodes that, it’s not converting, it’s degrading a file for no reason. So before anyone asks ‘which tool,’ the real question is ‘does this even need re-encoding.’ A lot of jobs don’t.
Where I’d push back slightly on the ‘native export first’ advice is that it assumes you still have the original app and a license for it. Plenty of people are handed a file made in something they don’t own. Telling them to go back to Photoshop or the original Office install isn’t always an option, and that’s exactly when a general tool becomes the realistic answer, not the fallback. Good rule in theory, less useful when you inherited someone else’s mess.
One thing that keeps biting people: batch converters that write output into the same folder with the same base name. If the source and target share an extension path or the tool auto-overwrites, you can lose originals in a single run. Point output to a separate folder every time. It sounds paranoid until it happens once.
If you want a simple version of all this: figure out whether the file needs repackaging or actual re-encoding, set the quality yourself instead of trusting the preset, run one test file, and keep the source somewhere the batch can’t touch it. The tool matters way less than those four habits.
CSV conversion needs its own warning because spreadsheet apps can quietly alter dates, long numbers, and IDs with leading zeros. For CSV or TSV, use a text-aware import, select UTF-8 and column types yourself, then inspect the saved file instead of trusting a generic converter.
A mislabeled file can make the whole cheat sheet point to the wrong tool. First identify the actual format with file properties or the file command, then convert a copy and test it in the destination app before processing the batch.