Can ChatGPT compress a video? (and what to use instead)

What happens when you ask ChatGPT to compress a video?

Nothing on OpenAI's help pages describes ChatGPT handing back a compressed video. Its page on uploads lists documents, spreadsheets, presentations, images and audio, and video isn't on the list. The only mention of video is a warning that MP4 and WebM files identified as video aren't supported as audio uploads. The same page, checked on 1 November 2026, sets these limits:

• Documents and presentations up to 512 MB a file, images up to 20 MB, and audio up to 512 MB (audio on paid plans only).
• Up to 80 files every 3 hours, and 3 file uploads a day on the Free plan.

For data analysis, OpenAI says ChatGPT writes and runs Python "in a stateful Jupyter notebook environment", and that this environment can't make web requests. That is the tool people hope will run a video encoder, which is the next question. If ChatGPT answers with steps or a command for you to run on your own computer, that part can be useful: see what to ask instead.

Can ChatGPT's Python tool run ffmpeg?

OpenAI doesn't say. Its help pages don't list the software installed in the Python environment, give no time limit for a run, and describe downloading only tables (as CSV files) and charts (as PNG images), not video. Because the environment can't reach the web, it can't fetch ffmpeg if it isn't already there.

In a thread on OpenAI's community forum, active in September 2026, several users reported that MP4 attachments were accepted in the chat but never reached the Python environment. That is a user report, not an OpenAI statement, but it fits the help pages: video isn't a supported route to rely on.

Two developer tools are documented in more detail, and neither lists ffmpeg. Google's Gemini API code execution lists its Python libraries (opencv-python and imageio, but no ffmpeg), stops each run after 30 seconds and "can't return other artifacts like media files". Anthropic's code execution tool for its API lists its pre-installed software, with no ffmpeg, and has no internet access. These are for programmers, not the chat apps, so take them as a hint about how such sandboxes are set up, not as the apps' rules.

Can Gemini, Claude or Copilot compress a video?

Not as a documented feature. Gemini takes video, but to analyse it. Claude can hand back files it makes in its code sandbox, but only up to 30 MB. Copilot doesn't list video at all.

From each company's help pages, checked on 1 November 2026 and linked under Sources. "Not described" means the page says nothing either way.

Gemini

Google's help page for Gemini Apps says each video can be up to 2 GB, and the total video length up to 5 minutes, or 1 hour with a Google AI Pro or Google AI Ultra plan. It describes asking questions about what you upload, not getting an edited file back.

Claude

Anthropic's upload page lists documents (PDF, DOCX, CSV and others) and images (JPEG, PNG, GIF, WebP), up to 500 MB a file in a chat. Its code execution and file creation feature, on every plan, runs code in a sandbox and lets you download what it makes, but "the maximum file size is 30MB per file for both uploads and downloads". That is about 14 seconds of 1080p phone video recorded at 17 Mbps (30 × 8 ÷ 17 = 14.1), so it could only help with a clip that is already small. Anthropic doesn't list the sandbox's software or mention video, and says it limits how long tasks can run. On Free, Pro, Max and Ultra plans the sandbox can install packages from approved sources, PyPI and Ubuntu's archive among them. We haven't tested whether it can install a video tool that way.

Microsoft Copilot

Microsoft's file upload page lists documents (PDF, DOCX, XLSX, PPTX), images (PNG, JPEG, PJP, JFIF) and text files (TXT, JSON, CSV, MD), up to 50 MB a file and 20 files in a conversation. Video isn't listed, and the page describes no code tool for the files you upload.

Will compressing a video help it upload to ChatGPT or Gemini?

Only where size is the limit. A smaller file is still a video, so compressing it won't put it on ChatGPT's, Claude's or Copilot's upload list. Gemini takes videos up to 2 GB, so there the limit you meet is usually length: 5 minutes in total on the free plan. A 5-minute 1080p video at 17 Mbps is about 640 MB (17 × 300 ÷ 8 = 637.5), well under 2 GB. Compressing keeps the length the same, so trim the video to the part you want to ask about instead.

Is it private to upload a video to an AI assistant?

Uploading sends a copy of the video to the company's servers. From then on, that company's rules decide how long it is kept and whether it can be used to improve its models. That is how any cloud service works, and it is worth knowing before you upload a video of your family, a patient or a work meeting. What each company says:

• Microsoft: files shared with Copilot are kept for no longer than 18 months and are not used to train its models.
• Google: with Keep Activity on, what you share with Gemini, uploads included, is saved in your activity; a subset of chats is read by human reviewers, and Google asks you not to enter confidential information you wouldn't want a reviewer to see.
• OpenAI: how long an uploaded file is kept depends on where it is stored, and whether it helps improve models depends on the service and your data settings.
• Anthropic: a deleted conversation leaves its back-end storage within 30 days; with the model-improvement setting on, chats may be kept, de-identified, for up to 5 years.

Our online video compressor works the other way round: your browser reads the video and makes the smaller copy on your phone or computer, and the video is never uploaded. The OctoZip app does the same on Android. Our privacy policy has the details for the site and the app.

What should I ask my AI assistant instead?

Ask for the numbers and the method, then do the compressing on your own device. Chatbots are good at explaining, and these sums are short enough to check by hand. For a 3-minute video bound for email:

1. "My video is 3 minutes long. What total bitrate fits under 25 MB?" Check the answer: bitrate in Mbps = size in MB × 8 ÷ seconds, so 25 × 8 ÷ 180 = 1.11 Mbps for picture and sound together. Leave a little room and aim for about 1 Mbps.
2. "Which resolution suits 1 Mbps?" Android's guide to sharing video pairs 5 Mbps and up with 1080p, 1.5 to 5 Mbps with 720p, and 1.5 Mbps or less with a smaller, SD-sized picture, so 1 Mbps calls for about 480p.
3. "Write an ffmpeg command for that and explain each part." ffmpeg is a free command-line tool; run it on your own computer and the video stays with you. A correct answer looks like this:

   ffmpeg -i input.mp4 \
     -vf scale=-2:480 \
     -c:v libx264 -b:v 900k \
     -maxrate 900k \
     -bufsize 1800k \
     -c:a aac -b:a 96k \
     -movflags +faststart \
     output.mp4

   That is 900 kbps for the picture plus 96 kbps for the sound, about 1 Mbps. The backslashes continue the command on the next line in a Mac or Linux terminal; on Windows, type it as one line without them. We ran it with ffmpeg 8.1 on a 3-minute 1080p test video of 388 MB and got a 480p MP4 of about 22.5 MB.
4. "What is the video limit on WhatsApp?" Then open the app's own help page to check: limits change, and a chatbot's answer can be out of date.

Limits from WhatsApp Help, Gmail Help and Discord's File Attachments FAQ, checked on 1 November 2026. Bitrate = limit × 8 ÷ 180 seconds, before leaving room: 100 × 8 ÷ 180 = 4.44, 25 × 8 ÷ 180 = 1.11 and 20 × 8 ÷ 180 = 0.89. Try your own numbers in the video bitrate calculator or the size limit checker, and see how to compress a video to a specific size.

How do I compress a video without uploading it?

In a browser, use our free online video compressor; on an Android phone, the OctoZip app. Both make the smaller copy on your device.

1. Open the online video compressor in recent Chrome or Edge, on a phone or a computer, and tap Choose a video.
2. Pick Target size and tap 20 MB (Discord), 25 MB (email) or 100 MB (WhatsApp), or type your own size. Small file, Medium and High quality are there too, and each setting shows an estimate of the new size.
3. Tap Compress video and keep the tab open until it finishes.
4. Play the new copy, then tap Download, or Share on a phone.

It does one video at a time, up to about 1–2 GB, and the copy is always an MP4. Safari is slower and sometimes stops part way.

OctoZip is our free Android app, with no ads. It compresses on the phone, works without an internet connection and never uploads your videos, and you can compare the copy with the original before you save it. It uses presets (Small file (easy share), Medium file, Best Quality) rather than a size in MB. It runs on Android 7.0 or later. The steps are in how to compress a video on Android.

GET IT ONGoogle Play

Questions people ask

Can ChatGPT make a video smaller for WhatsApp?

Not as a documented feature. Ask it for the bitrate that fits WhatsApp's 100 MB (4.4 Mbps for a 3-minute video), then compress on your phone or in the browser.

Can AI compress a video without losing quality?

No tool makes a video much smaller with no loss at all: a smaller file holds less detail, whether a chatbot, an app or a website makes it. A lower resolution at a sensible bitrate usually looks cleaner than full resolution squeezed into too few bits. More in does compressing a video reduce quality?

Do online and AI video compressors upload my video?

It depends on where the work happens. A tool that runs on a server needs the video uploaded; one that runs in your browser or on your phone doesn't. The tool's own privacy page should say which. Ours runs in the browser and never uploads. See also is it safe to use a video compressor app?

What this page doesn't cover

• We didn't upload a video to ChatGPT, Gemini, Claude or Copilot for this page. Everything about them comes from their own help pages and, where marked, a user report.
• It doesn't rank the assistants. Their features and limits change every few months, so check the date above.
• Business and workplace versions, such as ChatGPT Enterprise or Copilot with a work account, can differ from the consumer apps described here.
• Our online compressor does one video at a time, up to about 1–2 GB, in recent Chrome or Edge. The OctoZip app has no size-in-MB option, and batch compression needs OctoZip Pro.

Sources

Checked on 1 November 2026.

• OpenAI help pages: Uploading files and audio to ChatGPT, Data analysis with ChatGPT, Extracting insights with ChatGPT data analysis (CSV and PNG downloads) and Optimizing file uploads in ChatGPT Enterprise.
• OpenAI Developer Community: MP4 attachments accepted by ChatGPT but unavailable to the processing environment (user reports; thread active in September 2026).
• Gemini Apps Help: uploading files to Gemini Apps and the Gemini Apps Privacy Hub.
• Google AI for Developers: Gemini API code execution.
• Claude help pages: Upload files to Claude and Create and edit files with Claude; Anthropic privacy pages: How long do you store my data?; Claude API docs: Code execution tool.
• Microsoft Support: File upload in Microsoft Copilot and File formats supported by Microsoft Copilot.
• Android Developers: optimise video for sharing (bitrate and resolution).
• WhatsApp Help, Gmail Help and Discord's File Attachments FAQ for the limits in the table above.
• The ffmpeg command was run by us with ffmpeg 8.1 on macOS on 1 November 2026.

Related

• Free online video compressor (no upload)
• Is it safe to use a video compressor app?
• How do I compress a video to a specific size?
• What bitrate fits my file size?
• Can I compress a video on Android without installing an app?