X preflight
Prepare X image descriptions (up to the documented 1,000-character limit), captions, and hashtags before you post. Not affiliated with X Corp.
Live workspace
Results update as you edit. Nothing is sent to our servers unless you explicitly run AI image analysis.
Platform checklists update when you switch networks. Caption checks are shared across platforms.
Paste the caption or post text you plan to publish. Checks run locally in your browser.
Used for alt-text checks, contrast sampling, and optional AI review. Maximum 10 MB.
or drag and drop PNG, JPG, JPEG, or WEBP
Local preflight checks on captions and alt-text heuristics run in your browser and are not sent to our server.
Optional AI image analysis is separate and only runs when you choose "Analyze Image with AI."
Your results will appear here
Run local preflight to generate your readiness score, summary counts, and finding-by-finding guidance. Optional AI review appears after you analyze an image.
Measure WCAG contrast in your browser. Does not change your readiness score or call AI.
Color sampling and contrast calculations run in your browser. Image pixels are not sent for contrast measurement.
Opaque colors only. Transparency and overlays are not measured. Gradients and photos may need multiple background samples below.
Contrast ratio
21.00:1
PASS — Normal Text AA
Required for selected type (AA): 4.5:1
No image uploaded
Human review
Not automatic pass/fail—answer honestly before you publish.
Is important meaning conveyed by color alone?
Is text placed over a busy photo, gradient, or texture?
Is critical text small or thin in the image?
Is essential text only inside the image (not in caption)?
Would the message still make sense in grayscale?
Measured contrast plus human review prompts and optional AI observations.
Contrast passed
1
Contrast failed
0
Human review prompts
0
AI observations
0
Not measured as WCAG pass/fail
Measured ratios apply to solid foreground and background colors. This tool supports preflight review, not legal WCAG certification.
Approximate reading order and listening noise—local only, not an emulator.
This is an approximation for accessibility review. Actual output varies by platform, browser, operating system, assistive technology, and user settings. This is not an exact screen reader simulation.
Platform context: x (preview logic is not platform-specific yet).
Screen reader preview
Mostly Clear
Noise sources
1
Repeated emojis
No
Fancy Unicode
No
Excess hashtags
No
Duplicate caption/alt
No
Generic link language
No
Preflight reading order — not the platform accessibility tree.
Publish phase
Important items still need attention
Image description prepared
Automated signal
N/A
Important text in image represented accessibly
Automated signal
N/A
Alt text does not unnecessarily duplicate post copy
Automated signal
N/A
Multi-word hashtags reviewed for capitalization
Automated signal
Not checked
Repeated emoji reviewed
Automated signal
Not checked
Standard readable text (no decorative Unicode)
Automated signal
Not checked
Important information appears in post/description
Automated signal
Needs reviewCaption is empty.
Visual contrast measured where relevant
Automated signal
N/A
Link wording reviewed
Automated signal
Not checked
Video captions reviewed
Automated signal
N/AUse the Video Accessibility Checker (/video-accessibility-checker) for video captions.
Added/reviewed alt text on the platform
Publishing task
Needs reviewUser confirmation required — this tool cannot verify platform publishing.
Final review in platform composer
Publishing task
Needs reviewUser confirmation required — this tool cannot verify platform publishing.
Image description within X documented limit (1,000 characters)
Automated signal
N/A
All images reviewed individually (when posting multiple)
Publishing task
Needs reviewUser confirmation required — this tool cannot verify platform publishing.
Social platforms update their interfaces regularly. If the option appears in a different location, look for Alt Text, Alternative Text, Accessibility, Edit Photo, or Image Description controls.
Video Accessibility Checker — transcripts, timed captions, and SRT/WebVTT export for MP4/WebM.
X accessibility guidance recommends concise, descriptive image descriptions in regular sentence casing.
Consider capitalizing word boundaries in multi-word hashtags for readability.
Avoid excessive repeated emoji, which may add listening time for some assistive technologies.
If your post contains multiple images, add a useful image description to each meaningful image when publishing.
Accessible Content Preflight is an independent tool and is not affiliated with Instagram, Facebook, LinkedIn, or X.
Session-only confirmations—the tool cannot verify actions inside social apps.
Final checklist
Important items still need attention
Controls and labels can vary by post type and app version—confirm in X's publishing UI before you ship.
Generate a client-ready report from checks already run in this browser session. Export does not call AI or upload content.
No AI remediation has been generated for this session. Generate guidance in Fix Lab or the relevant checker tool first.
Run at least one preflight check (caption, contrast, AI, screen reader preview, or video captions) to generate a report.
Edit after applying fixes, then copy for publishing. Re-run preflight if you change content.
Based on current platform help documentation and accessibility best practices.
X currently documents a 1,000-character limit for image descriptions. Shorter, purposeful descriptions are usually easier to consume.
When posting multiple meaningful images, prepare and add a description for each image in X.
No. Copy your caption and description and apply them in X when posting.
No. This tool provides preflight guidance only and does not certify legal or standards compliance.
Platform guidance last reviewed 2026-10-08. UIs change; verify steps in the official app before publishing.
Automated accessibility guidance is not legal advice or certification. Some criteria require human review in the native app.