An applicant tracking system (ATS) is software that employers use to collect, sort, and rank job applications before a recruiter reviews them. If your resume does not score well against the job description inside the ATS, it may never reach a human reader — regardless of how qualified you are. Understanding how these systems work is the first step to making sure your resume actually gets seen.
What does an ATS actually do?
When you submit a resume through a company's online application portal, the ATS does several things automatically:
- Parses your resume — extracts your name, contact info, work history, education, and skills into a structured database record
- Matches keywords — compares the words and phrases in your resume against those in the job description
- Scores or ranks your application — assigns a relevance score based on keyword match, required qualifications, and sometimes years of experience
- Filters applications — resumes below a threshold may be automatically archived without recruiter review
Popular ATS platforms include Workday, Greenhouse, Lever, iCIMS, Taleo, and BambooHR. Each parses resumes slightly differently, which is why formatting matters as much as content.
ATS-friendly formatting: what to use and what to avoid
Many resumes fail ATS screening not because of content gaps but because the system cannot correctly parse the formatting. Follow these rules to ensure your resume is read accurately.
Use a simple, single-column layout
Multi-column resumes look polished in a PDF viewer but confuse ATS parsers that read left to right, top to bottom. A two-column resume often gets parsed in the wrong order, mangling your job history. Stick to a single-column format.
Avoid text boxes, tables, and headers/footers
Content placed inside text boxes, table cells, or document headers/footers is frequently skipped entirely by ATS parsers. Your contact information, if placed in a document header, may never be extracted. Put everything in the main body of the document.
Use standard section headings
ATS systems look for familiar section names: "Work Experience," "Education," "Skills," "Summary." Creative alternatives like "My Journey" or "What I Bring" may not be recognized, causing the parser to misfile your content.
Prefer DOCX over PDF for most applications
Modern ATS systems can usually read PDFs, but text-based DOCX files parse more reliably across all platforms. When in doubt, submit DOCX unless the posting specifies otherwise.
Use standard fonts at readable sizes
Fonts do not affect parsing, but very small text (under 10pt) may be missed by optical parsing tools. Use 10–12pt for body text. Avoid embedding text as an image — this is completely invisible to ATS.
Keyword strategy: how ATS systems match your resume
ATS keyword matching ranges from simple word counting to semantic analysis, depending on the platform. Most systems at least check for exact phrase matches. This means word choice matters significantly — "managed cross-functional teams" and "led cross-functional collaboration" both describe the same activity but will match different keyword strings.
Where to find the keywords to target
The job description is your primary source. Focus on:
- Words or phrases repeated more than once
- The job title itself and any alternate titles mentioned
- Specific tools, technologies, or methodologies listed as requirements
- Required certifications, degrees, or credentials
- Soft skills framed as specific phrases ("cross-functional collaboration," "data-driven decision making")
Where to place keywords in your resume
The skills section and the most recent work experience entries carry the most weight. Include important keywords in:
- Your professional summary (for the highest-priority terms)
- A dedicated skills or core competencies section
- Bullet points for relevant roles, integrated naturally into descriptions of what you did
Avoid placing keywords only at the end of the document or in a hidden section — some ATS systems weight keywords higher when they appear earlier.
Resume Tailor analyzes your resume against the job description, shows which keywords you matched and missed, and generates a tailored version — for $3.99.
What ATS cannot evaluate (and humans can)
ATS systems measure keyword presence and formatting parsability. They do not evaluate the quality of your writing, the logic of your career narrative, or whether your experience actually makes sense for the role. This is why optimizing for ATS without considering the human reader is a mistake.
The goal is a resume that clears ATS filters and reads compellingly to a recruiter. A keyword-stuffed resume that scores highly in an ATS but reads like a list of search terms will not get you an interview. Both layers matter.
How to check if your resume is ATS compatible
After formatting your resume, do a quick self-audit:
- Copy and paste the text of your resume into a plain text editor. If it reads in logical order without garbled sections, your formatting is likely ATS-safe.
- Compare your resume's language side by side with the job description. Count how many key phrases from the requirements appear in your resume.
- Use a tool that generates an ATS score — Resume Tailor shows a before-and-after match percentage so you can see exactly which keywords are present and which are missing.
Frequently asked questions
What percentage of resumes are rejected by ATS?
Estimates vary, but many HR professionals report that 70–75% of resumes are filtered out by ATS before a recruiter sees them. Most rejections happen because the resume lacks specific keywords from the job description, not because the candidate is unqualified.
Does ATS read PDF resumes?
Most modern ATS systems can parse standard PDFs, but text-based PDFs parse more reliably than image-based or scanned PDFs. DOCX files are generally the safest format. Avoid PDFs created from scanned documents.
What fonts are ATS friendly?
ATS systems parse text, not visual formatting, so the font itself rarely matters. What does matter is that you avoid text boxes, headers, footers, and columns, which some ATS parsers struggle to read in the correct order.
Is a two-page resume bad for ATS?
No — ATS systems do not penalize two-page resumes. The two-page concern is a human-reader preference. For ATS purposes, length does not matter; keyword coverage and formatting simplicity do.