What Is an ATS and What Does It Actually Do?
An Applicant Tracking System (ATS) is software that employers use to collect and manage job applications. Some systems parse resume text into structured fields such as contact details, skills, and work history; screening rules and recruiter workflows vary by employer.
A parser can miss or reorder content in a complex document, and an employer may search for particular qualifications. Neither outcome means every application is automatically scored or rejected, and no public checker can predict a specific employer's decision.
Common platforms include Workday, Greenhouse, Lever, iCIMS, Ashby, and SAP SuccessFactors. Their configurations differ by customer, so treat general ATS guidance as risk reduction rather than a guaranteed pass.
The 6 Most Common ATS Platforms in 2026
Each ATS parses resumes slightly differently. Here are the platforms you're most likely to encounter:
Workday — used by large enterprises (60% of Fortune 500). Known for strict formatting requirements. Parses PDFs well but struggles with multi-column layouts.
Greenhouse — popular with tech companies and startups. Good at parsing modern resume formats but penalises missing keywords heavily.
Lever — combines ATS with CRM. Relatively forgiving on formatting but keyword matching is strict.
iCIMS — common in healthcare, finance, and government. Older parser technology — avoid complex formatting entirely.
Ashby — growing rapidly in tech. Modern parser that handles most formats well, but still keyword-dependent.
SAP SuccessFactors — enterprise-grade, common in manufacturing and large corporations. Conservative parser — stick to simple, single-column layouts.
10 Formatting Rules Every ATS-Friendly Resume Must Follow
Resume parsing can be affected by missing role language and hard-to-read document structure. These ten conservative practices reduce risk, but the ResumeAI text checker cannot inspect the original file layout:
1. Use a single-column layout. Multi-column resumes confuse most ATS parsers because they read left-to-right, top-to-bottom. Two columns cause text to get interleaved.
2. No images, graphics, or icons. ATS can't read visual elements. Your skills chart or headshot is invisible to the parser.
3. Use standard section headings. Stick to 'Work Experience', 'Education', 'Skills', and 'Summary'. Creative headings like 'My Journey' or 'What I Bring' won't be recognised.
4. No headers or footers. Many ATS platforms strip headers and footers entirely. If your name and contact info are in a header, the parser may miss them completely.
5. No text boxes or tables. Content inside text boxes is often skipped. Tables can cause data to appear in the wrong order.
6. Use standard bullet characters. Round bullets are safest. Arrows, diamonds, and custom symbols may be converted to garbled characters.
7. Consistent date formatting. Pick one format (e.g., 'Jan 2024 – Present') and use it everywhere. Mixed formats confuse date-range extraction.
8. Readable font size (10pt+). Anything smaller may not parse correctly. Stick to 10-12pt for body text.
9. Contact information at the top. Name, email, phone, and LinkedIn URL should be in the first few lines of the document — not in a sidebar or header.
10. Save as PDF or DOCX. PDF is generally safest because it preserves formatting. Some older ATS platforms prefer DOCX. Avoid image-based PDFs (scanned documents).
How to Find the Right Keywords for Your Resume
Job-description language is one useful input when tailoring a resume. Employer systems and recruiters may evaluate it alongside required qualifications, application answers, work authorization, and other criteria.
The manual approach: Read the job description carefully. Highlight every hard skill (Python, Tableau, GAAP), soft skill (collaboration, leadership), certification (PMP, AWS Certified), and tool (Jira, Salesforce) mentioned. Then check your resume for each one.
The automated approach: Use a keyword extraction tool to surface terms recognized by its taxonomy, then compare those results with your own reading. Any taxonomy has blind spots, especially for niche roles and non-English text.
Use the employer's wording only when it truthfully describes your experience. ResumeAI groups some variants and synonyms, but it cannot model the matching behavior of every ATS configuration.
Step-by-Step: Checking Your Resume with ResumeAI
Here's how to use our free tool to check your resume against any job description:
Step 1: Go to ResumeAI and paste an English job description into the Keyword Extractor. The NLP engine identifies terms recognized by its taxonomy, including skills, certifications, and job-title terms.
Step 2: Paste your resume into the Gap Analysis tool alongside the job description. You'll see an explainable taxonomy score and a list of recognized terms that are present or missing.
Step 3: Run the ATS Compliance Checker for 15 text-based signals, then inspect the original document's columns, margins, fonts, images, headers, and footers yourself.
Step 4: Use the AI Bullet Rewriter to naturally incorporate missing keywords into your experience bullets — without inventing facts or experience you don't have.
Step 5: Generate a tailored cover letter and download your optimised resume as a clean PDF.
Common ATS Myths Debunked
Myth: 'I need to stuff my resume with keywords.' — Reality: Keyword stuffing (repeating the same word 20 times) actually hurts you. Modern ATS platforms detect this and flag it as spam. Use keywords naturally in context.
Myth: 'ATS can't read PDFs.' — Reality: This was true 10 years ago but not anymore. Most modern ATS platforms parse PDFs well. The exception is image-based PDFs (scanned documents). Always use a digitally created PDF, not a scan.
Myth: 'I should use a plain text resume.' — Reality: Plain text (.txt) resumes lose all formatting and look unprofessional. PDF or DOCX is the standard. The key is simple formatting, not no formatting.
Myth: 'White text keywords will trick ATS.' — Reality: Some people add hidden white text with keywords. Modern ATS platforms detect this and many will reject your application automatically. Don't risk it.
Myth: 'Creative resumes stand out.' — Reality: Creative formatting (infographics, timelines, icons) hurts you with ATS. Save creativity for portfolios. Your resume needs to be machine-readable first, human-readable second.
15-Point ATS Compatibility Checklist
Before you submit any application, verify your resume passes these 15 checks:
1. Single-column layout (no tables or columns)
2. No images, graphics, or icons
3. Standard section headings (Experience, Education, Skills)
4. No content in headers or footers
5. No text boxes
6. No special characters in headings
7. Consistent date formatting throughout
8. Standard bullet characters (round dots)
9. No colour-coded text for meaning
10. Font size 10pt or larger
11. Contact info at the top (not in a sidebar)
12. No hyperlink-only text (spell out URLs)
13. PDF or DOCX file format
14. Adequate page margins (0.5 inch minimum)
15. Logical section order (Contact → Summary → Experience → Education → Skills)
You can run all 15 checks automatically with the free ATS Compliance Checker on ResumeAI.