File Format

File Format Your File Format Guide
Information, news, and discussions about file extensions and which products support them.

Think spreadsheets are safe just because they aren’t executable .exe binaries? Think again! ⚠️When your web app exports ...
29/10/2026

Think spreadsheets are safe just because they aren’t executable .exe binaries? Think again! ⚠️
When your web app exports user data to Excel or CSV, unescaped formulas can lead to Formula Injection, malware delivery through macros, or server vulnerabilities like XXE when parsing uploads.
Our latest developer guide breaks down practical ways to secure your spreadsheet generation, sanitization, and parsing pipelines: 👉 https://blog.fileformat.com/spreadsheet/spreadsheet-security-best-practices-for-developers/
Check it out to learn how a simple single quote (') prefix can prevent remote data exfiltration and protect your users.

Learn essential spreadsheet security best practices for developers. Prevent formula injection (CSV/XLSX), sanitize input, manage access controls, and avoid data leaks.

Still exporting your 3D models as STL files? It might be time to leave 1987 behind.While STL has been the industry stand...
22/10/2026

Still exporting your 3D models as STL files? It might be time to leave 1987 behind.

While STL has been the industry standard for decades, it drops almost all critical data—carrying only basic surface geometry. That means no scale units, no color definitions, no material properties, and zero slicer presets. Every time you import an STL, you essentially rebuild the job from scratch.

Enter 3MF (3D Manufacturing Format): an open-source, XML-based archive supported by major industry leaders like Microsoft, Ultimaker, Bambu Lab, and Prusa. It bundles full assemblies, units, multicolor data, and slicer profiles into a compact, error-free file.
Check out our full breakdown comparing 3MF and STL to see why modern additive workflows are making the switch: 👉 https://blog.fileformat.com/cad/3mf-vs-stl-why-3mf-could-replace-stl-for-modern-3d-printing-workflows/

Still exporting to STL? Discover why the modern 3MF format outclasses STL in color data, file size, print settings, and overall reliability for 3D printing.

Choosing the right audio format for your web app isn't just a technical preference—it impacts loading speed, server cost...
16/10/2026

Choosing the right audio format for your web app isn't just a technical preference—it impacts loading speed, server costs, and cross-browser reliability. 🎧

Should you default to WebM (Opus) for its ultra-low latency and lightweight compression, or stick to the universal, battery-friendly hardware support of MP4 (AAC)?

In our latest guide, we compare both formats across compression efficiency, streaming response times, mobile battery footprint, and browser support. We've also included production-ready fallback code snippets and FFmpeg recipes you can drop into your app today.
👉 Check out the full breakdown here: https://blog.fileformat.com/audio/webm-audio-vs-mp4-audio-what-works-best-for-web-applications/

What is your go-to audio format for web apps? Drop your stack in the comments! 👇

Cut bandwidth without sacrificing audio quality. Explore our technical comparison of WebM Audio vs MP4 Audio to determine the ideal codec for your app stack.

Digitizing a modern printed book is relatively simple, but what happens when you are deciphering 18th-century handwritte...
07/10/2026

Digitizing a modern printed book is relatively simple, but what happens when you are deciphering 18th-century handwritten court records, medieval marginal notes, or curved cursive scripts?

Standard OCR outputs like plain text or simple "sandwich" PDFs completely strip away the spatial context that historians and archivists need. To capture real handwriting, archives rely on specialized schemas capable of tracking polygon boundaries and undulating baselines.
In our latest guide, we explore:
🔹 Why PAGE XML leads the handwritten text recognition (HTR) space.
🔹 How ALTO XML v4+ supports massive library repositories.
🔹 Where hOCR fits into quick web-based search.
🔹 How raw transcripts transform into scholarly TEI-XML critical editions.

If you work in libraries, archives, genealogy, or digital history, check out the full guide to see which format fits your preservation workflow: https://blog.fileformat.com/ocr/ocr-file-formats-for-historical-and-handwritten-documents/

Discover the best OCR and HTR file formats for historical manuscripts and handwritten archives, comparing ALTO, PAGE XML, hOCR, and TEI-XML.

Before you click "Enable Content" on that incoming spreadsheet, here is why you need to pause!Have you ever wondered why...
01/10/2026

Before you click "Enable Content" on that incoming spreadsheet, here is why you need to pause!

Have you ever wondered why Excel warns you every time you open certain files? It usually comes down to two letters at the end of the filename: XLSX vs. XLSM.
XLSX files are standard data workbooks. They hold numbers, charts, and formulas—but they cannot run background programs or executable scripts.

⚠️ XLSM files are macro-enabled. They can automate complex tasks with a single click, but malicious actors also use that same capability to install hidden malware, hijack systems, or siphon company data. If your team regularly shares spreadsheets or receives attachments from outside vendors, knowing what’s happening beneath the surface will keep your workstation safe.
Check out our comprehensive guide to Excel file security, where we explain how macros work, how attackers exploit them, and the simple settings you can toggle to protect your PC.

Read the full article: https://blog.fileformat.com/spreadsheet/excel-file-security-explained-xlsx-xlsm-and-macro-risks/

Understand the real security differences between XLSX and XLSM files, how macro-based attacks execute, and how to defend your organization against malicious spreadsheets.

If you’re building an audio streaming app, voice platform, or live video service, your codec choice makes or breaks user...
23/09/2026

If you’re building an audio streaming app, voice platform, or live video service, your codec choice makes or breaks user retention.
But when should you pick Opus, and when should you stick to AAC?

🔹 Opus is the undisputed champion of real-time communication. With sub-26ms latency, built-in packet loss recovery, and a dynamic hybrid engine (combining SILK for speech and CELT for music), it runs circles around older codecs on unpredictable cellular networks. Plus, it's 100% open-source and royalty-free.

🔹 AAC remains the universal king of pre-recorded media. Thanks to dedicated silicon decoders on practically every smartphone, smart TV, and car head unit, it gives your users hours of transparent music playback without chewing through battery life.
We just published a detailed engineering guide breaking down:

âś… Perceptual listening benchmarks (6 kbps to 160 kbps)
âś… Latency profiles: Opus interactive mode vs AAC-ELD vs AAC-LC
âś… Patent licensing & commercial bundling pitfalls
âś… How modern platforms build hybrid pipelines using both

đź”— Read the full guide here: https://blog.fileformat.com/audio/opus-vs-acc-which-audio-codec-is-best-for-streaming-apps/

Comparing Opus vs AAC for streaming apps. Learn how latency, bitrate efficiency, battery consumption, and licensing impact your app architecture.

Tired of treating .pptx files like unpredictable black boxes? When high-level libraries like Apache POI or python-pptx h...
17/09/2026

Tired of treating .pptx files like unpredictable black boxes?
When high-level libraries like Apache POI or python-pptx hit their limits or produce weird layout bugs, the best path forward is looking at the raw OpenXML underneath.
Under the hood, a modern .pptx file is just a zip package filled with XML schemas, media files, and relationship trees. But working with them directly requires knowing the quirks:
o Why shapes inherit "invisible" styling across a 4-tier cascade (Theme âž” Master âž” Layout âž” Slide).
o How coordinates work in English Metric Units (EMUs) without floating-point errors.
o How to inspect any feature using a clean before-and-after diff workflow.
o How to safely parse, modify, and repack presentations in serverless runtimes without heavy dependencies.
I put together a complete developer's guide covering the architecture, code patterns, and security guardrails you need to reverse engineer PowerPoint files with confidence.
Read the full breakdown: https://blog.fileformat.com/presentation/pptx-reverse-engineering-understanding-powerpoint-files-internally/

Discover what really lives inside a `.pptx` file. Learn how OpenXML packaging, relationship graphs, shapes, and drawing markup work under the hood.

Struggling with performance, compatibility, or storage when dealing with How Compression Works Inside EPUB, DOCX, XLSX, ...
10/09/2026

Struggling with performance, compatibility, or storage when dealing with How Compression Works Inside EPUB, DOCX, XLSX, and PPTX?
If you rename a .docx, .xlsx, .pptx, or .epub file to .zip and double-click it, something surprising happens: it doesnât throw an error. Your operating system opens it as a folder packed with subdirectories, XML configuration files, styling sheets, fonts, and embedded images. Here are the core takeaways you should know:

• The Container Architecture: Disguised ZIP Packages
• A single bit flip could corrupt the entire file structure.
• Embedding images caused file sizes to balloon unpredictably.
• Parsing required reverse-engineering dense binary specifications.

Dive into the details and discover practical solutions for your workflows and software projects.

👉 Read the complete guide: https://blog.fileformat.com/compression/how-compression-works-inside-epub-docx-xlsx-and-pptx/

Ever wondered what's under the hood of a .docx or .epub file? Explore how ZIP packaging and DEFLATE compression keep modern office documents and ebooks lightweight and organized.

Still right-clicking and saving everything as a .zip? You might be leaving gigabytes of wasted storage and minutes of tr...
03/09/2026

Still right-clicking and saving everything as a .zip? You might be leaving gigabytes of wasted storage and minutes of transfer time on the table.
While ZIP is the undisputed king of universal convenience, modern workflows often demand more. If you are backing up codebases, handling server snapshots, or sending encrypted deliverables, formats like 7Z and TAR.GZ can do the job significantly better. In our latest guide, we benchmark all three across speed, compression ratio, security, and OS support:
• ZIP: Instant random access and works on every device natively.
• 7Z: Unbeatable compression ratios and military-grade header encryption.
• TAR.GZ: Flawless preservation of Linux permissions and ideal for data pipelines.
Check out the full comparison breakdown to pick the exact right format for your next project: https://blog.fileformat.com/compression/zip-vs-7z-vs-tar.gz-which-compression-format-should-you-use/

Wondering whether to use ZIP, 7Z, or TAR.GZ? Compare compression ratios, extraction speeds, system compatibility, and security to choose the right format.

Building an audio pipeline, game engine, or speech recognition backend?  While WAV and FLAC deliver the exact same lossl...
28/08/2026

Building an audio pipeline, game engine, or speech recognition backend? While WAV and FLAC deliver the exact same lossless audio fidelity, their system performance profiles are completely different:

• WAV is uncompressed—giving you instantaneous DMA playback with zero CPU decompression, but massive file sizes.
• FLAC compresses your audio by 40–60% using smart mathematical prediction without losing a single sample, dramatically cutting cloud bandwidth and storage bills.

We put together a comprehensive developer guide breaking down the binary internals, container structures, CPU vs. I/O trade-offs, and implementation code in Rust and Python.

Check out the full guide here:

Explore the architectural differences between WAV and FLAC. Learn how RIFF and native FLAC frames work, decoding overhead, and when to use each in production.

Address

Aspose Pty Ltd, Suite 163, 79 Longueville Road
Lane Cove, NSW
2066

Alerts

Be the first to know and let us send you an email when File Format posts news and promotions. Your email address will not be used for any other purpose, and you can unsubscribe at any time.

Contact The Business

Send a message to File Format:

Shortcuts

Share

Nearby computer & electronics services